AP PHYSICS Mr. Brennan Cudd

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1 AP PHYSICS Mr. Brennan Cudd The attached work is due back to Azle High School by: June 8th 10:00 12:00 & 1:00 3:00 Work will not be accepted after the dates listed above. If you are out of town on the above listed dates, all assignments must be submitted to the AHS Counseling office prior to June 8 th. Summer counseling office hours are 7:30-11:30 am & 12:30 4:00 pm Mr. Brennan Cudd Attach this completed form to the front of summer work. Student Name: Student Parent Name: Parent Parent Phone Number:

2 Dear AP Physics prospective student: 2017 AP Physics Summer Work This document has four different assignments covering four topics. On Shayna Reasoner s school webpage you will find these same assignments plus a PowerPoint in PDF format that you are more than welcome to download in assisting you in learning about the topics covered in the four assignments. The four assignments cover: (1) Rotational Mechanics Torque (2) Rotational Mechanics Dynamics (3) Rotational Mechanics Angular Momentum (4) Universal Gravitation WEBSITE: The website can be found from the Azle High School home page: Go to Click on Select a School at the top Choose Azle High School Click on Staff and Organizations Click on the name (Shayna Reasoner) AP Physics Summer Work can be accessed from the left-hand menu. In completing the assignments, please write your answers in the answer blanks in capital letters and then bubble in the answers on the Scantron cards that are provided (4). It is very important that you turn in BOTH the Scantron cards as well as this packet. Also note that if you come up with an answer that is not listed as a possible answer, please leave the answer blank on the Scantron card and write what you think is the correct answer on the summer worksheet. The attached work is due back to Azle High School by: June 8th 10:00 12:00 & 1:00 3:00 Work will not be accepted after the dates listed above. If you are out of town on the above listed dates, all assignments must be submitted to the AHS Counseling office prior to June 8 th. Summer counseling office hours are 7:30-11:30 am & 12:30 4:00 pm

3 Name AP Physics Summer Work Rotational Mechanics Torque For Questions 1 5, A = True & B = False (1) The distance between a turning axis and the point of contact of a perpendicular 1) force is called the fulcrum. (2) Torque is the product of a force exerted on an object times the lever arm. 2) (3) In order for a seesaw to be in rotational equilibrium, the sum of the torques acting 3) on it need not be balanced if one person sits closer to the fulcrum than the other person. (4) Torque is defined as tangential force times mass. 4) (5) Suppose you try loosening a nut with a wrench, and the nut doesn't give at all. You increase 5) your chance of success if you exert a larger force. (6) A heavy boy and a light girl are balanced on a mass-less seesaw. If they both move 6) forward so that they are one-half their original distance from the pivot point, what will happen to the seesaw? A) The side the girl is sitting on will tilt downward. B) The side the boy is sitting on will tilt downward. C) The seesaw will start rotating counter-clockwise. D) Nothing, the seesaw will still be balanced. (7) A vault is opened by applying a force of 300 N perpendicular to the plane of the door, 7) 0.8 m from the hinges. Find the torque due this force about an axis through the hinges. A) 120 N-m B) 240 N-m C) 300 N-m D) 360 N-m (8) A meter stick is supported by a knife edge at the 0.5 m mark. Ryan hangs masses of 8) 0.40 kg and 0.60 kg from the 0.2 m and 0.8 m marks, respectively. Where should Ryan hang a third mass of 0.30 kg to keep the stick balanced (rotational equilibrium)? A) 0.15 m B) 0.20 m C) 0.25 m D) 0.30 m (9) Two equal forces are applied to a door. The first force is applied at the midpoint of the 9) door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force exerts the greater torque? A) both exert equal non-zero torques B) the first at the midpoint C) the second at the doorknob D) both exert zero torques

4 Page 2 (10) The bolts on a car wheel require tightening to a torque of 90 N m. If a 0.3-m long wrench 10) is used, what is the magnitude of the force required when the force is perpendicular to the wrench? A) 150 N B) 30 N C) 300 N D) 15 N (11) A 60-kg boy sits on a seesaw 1.0 m from the fulcrum. What distance from the fulcrum 11) should a 30-kg girl should sit in order to balance the seesaw? A) 1.3 m B) 2.0 m C) 2.5 m D) 3.0 m (12) Mary pushes a metal pipe 1.5 m out past the edge of a building so that it is just perfectly 12) balanced from tipping over while a basket weighing 100 N hangs on the end. If the uniform pipe weighs 200 Newtons how far away from the edge is the center of gravity of the pipe located? A) 0.50 m B) 0.75 m C) 1.25 m D) 1.50 m (13) A bucket filled with water has a mass of 23 kg and is attached to a rope that is wound 13) around a cylinder with a diameter of 0.10 meters at the top of the well. What torque does the weight of the water and bucket produce on the cylinder? (g = 9.8 m/s 2 ) A) 34 N m B) 23 N m C) 17 N m D) 11 N m

5 Page 3 (14) Jack and Jill are sitting on opposite sides of a seesaw; each 2 meters from the fulcrum. If 14) Jack has a mass of 60 kg and Jill has a mass of 50 kg how far can Mighty Mutt (mass = 25 kg) sit from Jill so that all are in rotational equilibrium? A) 0.8 m B) 1.0 m C) 1.2 m D) 1.6 m (15) If a clockwise force is applied a perpendicular distance from a pivot point in the plane of 15) this paper, what is the direction of the resultant torque vector? A) clockwise B) toward the top of this paper C) perpendicular and into the paper D) perpendicular and out of the paper (16) A uniform board that weighs 500 N is supported by two bricks. Two bricks, one at each 16) end of the board, support the board. If the board is 3 meters long and a sack of sand weighing 400 Newtons is located 0.5 meters from the middle of the board, how much weight does each brick support? A) 900 N and 517 N B) 383 N and 517 N C) 383 N and 450 N D) 1550 N and 900 N (17) Morgan and Abby have a uniform pole that is 2 meters long and weighs 50 Newtons. The 17) girls are to carry a 100 Newton backpack hanging from the pole from one class to another. While Morgan isn t looking Abby shifts the backpack so that the backpack is only 75 cm (0.75 m) from Morgan. If the ends of the pole are supported by the girls how much weight does Morgan carry? A) 87.5 N B) 62.5 N C) 150 N D) 75.0 N

6 Page 4 (18) A utility pole that lies on the ground weighs 4000 Newtons is non-uniform and 10 m long. 18) If the center of mass for the pole is 2 meters from the heavier end and Carl wants to pick up the lighter end of the pole, what is the minimum force he will have to use? A) 4000 N B) 100 N C) 500 N D) 800 N (19) When Kin opens a door for his mother he pulls the door handle with a force of 20 Newtons. 19) If his arms make a 30 angle with the door and the door handle is 0.9 meters from the door hinges, how much torque does Kin exert on the door? A) 9 N m B) 45 N m C) 4.5 N m D) 16 N m (20) A pulley with a diameter of 20 centimeters has a 500 gram mass tied to a string that passes 20) over the pulley and is just hanging. What torque is the mass exerting on the pulley? A) 9.8 N m B) 0.98 N m C) 490 N m D) 0.49 N m

7 Name AP Physics Summer Work Rotational Mechanics Dynamics (1) Two uniform solid spheres, A and B have the same mass. The radius of sphere B is twice 1) that of sphere A. The axis of rotation passes through the center of each sphere. Which one of the following statements concerning the moments of inertia of these spheres is true? A) The moment of inertia of A is one-fourth that of B. B) The moment of inertia of A is one-half that of B. C) The moment of inertia of A is 5/4 that of B. D) The moment of inertia of A is 5/8 that of B. (2) A slender 1.5-m rod, with mass 1.25-kg, is rotated about the perpendicular axis through 2) its center. What is its resistance to this rotation? A) kg - m 2 B) kg - m 2 C) 1.88 kg - m 2 D) 2.81 kg - m 2 (3) A kg rubber stopper is attached to a 0.50-m long string. What is its moment of inertia 3) as it twirls around a horizontal circle? A) kg - m 2 B) kg - m 2 C) kg - m 2 D) 313,000 kg - m 2 (4) A pulley, with a radius of m, has a rotational inertia of kg-m 2. What is the 4) mass of the pulley? A) kg B) kg C) kg D) kg (5) When a net torque is applied to a rigid object, it always produces a 5) A) constant acceleration. B) rotational equilibrium. C) constant angular velocity. D) change in angular velocity. (6) A bicycle wheel, a hollow sphere, and a solid sphere each have the same mass and radius. 6) They each rotate about an axis through their centers. Which has the greatest moment of inertia and which has the least? A) The wheel has the greatest; the hollow sphere has the least. B) The wheel has the greatest; the solid sphere has the least. C) The hollow sphere has the greatest; the solid sphere has the least. D) The hollow sphere has the greatest; the wheel has the least. E) The solid sphere has the greatest; the hollow sphere has the least.

8 Page 2 Rotational Dynamics (7) You are given two hoops (I = mr2), which are (1) brass and (2) wood, and two 7) cylinders (I = ½ mr2), which are (3) brass and (4) wood; each has radius R. If all are released from the same starting line at the same time, the one(s) that reach the bottom first are A) 1 and 2 B) 3 and 4 C) 1, 2, 3, and 4 D) 1 E) 3 (8) Starting from rest at the same time, a coin and a ring roll down an incline without slipping. 8) Which reaches the bottom first? A) The ring reaches the bottom first. B) The coin reaches the bottom first. C) They arrive at the bottom simultaneously. D) The winner depends on the relative masses of the two. E) The winner depends on the relative diameters of the two. (9) To increase the moment of inertia of a body about an axis, you must 9) A) increase the angular acceleration. B) increase the angular velocity. C) decrease the angular velocity. D) make the body occupy less space. E) place part of the body farther from the axis. (10) The rotational inertia of an object about an axis depends on the 10) A) angular velocity about the axis. B) torque about the axis. C) angular acceleration about the axis. D) linear acceleration about the axis. E) mass distribution about the axis. (11) A string is wrapped around a pulley of radius 0.10 m and moment of inertia 0.15 kg - m 2. 11) The string is pulled with a force of 12 N. What is the magnitude of the resulting angular acceleration of the pulley? A) 18 rad/s 2 B) 0.13 rad/s 2 C) rad/s 2 D) 8.0 rad/s 2

9 Page 3 Rotational Dynamics (12) A 2.0 kg rock is tied to a 0.50 m long string and swung around in a circle with a constant 12) angular velocity of 12 rads/s. What is the net torque on the rock about the center of the circle? A) 72 N - m B) 6.0 N - m C) 0 N - m D) 12 N - m (13) A string is wrapped around a pulley of radius 0.05 m and rotational inertia of 0.2 kg - m 2. 13) If the string is pulled with a force F, and the resulting angular acceleration of the pulley is 2 rads/s 2, what is the magnitude of F? A) 0.4 N B) 2 N C) 8 N D) 16 N (14) A 50 N - m torque acts on a wheel of rotational inertia 150 kg - m 2. If the wheel starts 14) from rest, how long will it take the wheel to make one revolution? A) 0.33 second B) 0.66 second C) 2.4 seconds D) 6.1 seconds (15) Jacob starts to push a merry-go-round, initially at rest, with a tangent-to-the-merry-go-round 15) force of 50 Newtons. The merry-go-round has a mass of 200 kg and a radius of 2.0 meters. What is the angular acceleration of the merry-go-round, assuming no friction and the force is constant? A) rads/sec 2 B) rads/sec 2 C) rads/sec 2 D) rads/sec 2 (16) A wheel with a moment of inertia 2.00 kg m 2 has a net torque of 2.50 N-m applied to it. 16) What angular acceleration does it experience? A) rads/sec 2 B) 1.25 rads/sec 2 C) 2.00 rads/sec 2 D) 2.50 rads/sec 2

10 Page 4 Rotational Dynamics (17) The drive chain in a bicycle is applying a torque of N-m to the wheel of the bicycle. 17) Treat the wheel as a hoop with a mass of kg and a radius of m. What is the angular acceleration of the wheel? A) 20.8 rads/sec 2 B) 10.4 rads/sec 2 C) 3.43 rads/sec 2 D) 1.06 rads/sec 2 E) 5.20 rads/sec 2 (18) When a ceiling fan rotating with an angular speed of 2.65 rad/s is turned off, a frictional 18) torque of 0.12 N-m slows it to a stop in 19.5 seconds. What is the moment of inertia of the fan? A) kg - m 2 B) kg - m 2 C) kg - m 2 D) 4.42 kg - m 2 (19) What constant torque, in the absence of friction, must be applied to a wheel to give it an 19) angular velocity of 50 rad/s if it starts from rest and is accelerated for 10 seconds? The moment of inertia of the wheel about its axle is 9.0 kg - m2. A 4.5 N - m B) 9.0 N - m C) 45 N - m D) 30 N - m E) 60 N - m (20) A wheel slows from 20 rad/s to 12 rad/s in 5 s under the influence of a constant frictional 20) torque. In these 5 seconds, the wheel turns through an angle of A) 2.4 rad B) 43 rad C) 60 rad D) 80 rad E) 100 rad

11 Name AP Physics Summer Work Rotational Mechanics Angular Momentum (1) If the angular momentum of a system is constant, which of the following statements must 1) be true? A) A constant torque acts on each part of the system. B) Zero net torque acts on each part of the system. C) A constant external torque acts on the system. D) Zero net torque acts on the system. (2) The angular momentum of a flywheel about its axis is 925 kg-m 2 /s. If its moment of 2) inertia about the same axis is 2.50 kg-m 2, its angular velocity is what amount? A) 370 rev/min B) 62 rev/min C) 2210 rad/s D) 370 rad/s (3) To increase the moment of inertia of a body about an axis, you must 3) A) increase the angular acceleration. B) increase the angular velocity. C) make the body occupy less space. D) place part of the body farther from the axis. (4) A 2.0-g particle moves at a constant speed of 3.0 mm/s around a circle of radius 4.0 mm. 4) Find the magnitude of the angular momentum of the particle. A) kg-m 2 /s B) kg-m 2 /s C) kg-m 2 /s D) kg-m 2 /s (5) A 2.0-kg particle moves directly eastward at a constant speed of 4.5 m/s along an east-west 5) line. What is the magnitude of its angular momentum about a point that lies 6.0 meters north of the line? A) 54 kg-m 2 /s B) 90 kg-m 2 /s C) 27 kg-m 2 /s D) 12 kg-m 2 /s

12 Page 2 (6) You stand on a frictionless platform that is rotating at an angular speed of 1.5 rev/s. Your 6) arms are outstretched, and you hold a heavy weight in each hand. The moment of inertia of you, the extended weights, and the platform is 6.0 kg-m 2. When you pull the weights in toward your body, the moment of inertia decreases to 1.8 kg-m 2. What is the resulting angular speed of the platform? A) 5 rev/s B) 0.2 rev/s C) 0.5 rev/s D) 3.33 rev/s (7) A skater is spinning at 32.0 rad/s with her arms and legs extended outward. In this position 7) her moment of inertia with respect to the vertical axis about which she is spinning is 45.6 kg-m 2. She pulls her arms and legs in close to her body changing her moment of inertia to 17.5kg-m 2. What is her new angular velocity? A) 14.6 rads/s B) 83.4 rad/s C) 12.3 rads/s D) 56.0 rad/s (8) Say that NASA planned to put a satellite into a circular orbit around Pluto for studies, but 8) the situation got a little out of hand and the satellite ended up with an elliptical orbit. At its nearest point to Pluto, meters, the satellite zips along at 9,000 meters per second. At its farthest point the satellite is meters. What is its speed at this farthest location? A) 2970 m/s B) 980 m/s C) 3300 m/s D) 2700 m/s (9) Calculate the angular momentum of a phonograph record (LP) rotating at 33 1 /3 rev/min. 9) An LP has a radius of 15 cm and a mass of 150 grams. A) kg-m 2 /s B) kg-m 2 /s C) kg-m 2 /s D) kg-m 2 /s (10) A cylinder of mass 250 kg and radius 2.60 m is rotating at 4.00 rad/s on a frictionless surface 10) when two more identical nonrotating cylinders fall on top of the first. Because of friction between the cylinders they will eventually all come to rotate at the same rate. What is this final angular velocity? A) 1.33 rads/s B) 7.50 rad/s C) 3.75 rads/s D) 0.75 rad/s

13 Page 3 (11) A person stands, hands at his side, on a platform that is rotating at a rate of 1.3 rev/s. If he 11) raises his arms to a horizontal position, the speed of rotation decreases to 0.80 rev/s. By what factor has the moment of inertia of the person changed? A) 1.3 times more B) 1.6 times more C) 0.62 times more D) 0.62 times less (12) A figure skater can increase her spin rotation rate from an initial rate of 1.0 revolution every 12) 2 seconds to a final rate of 3.0 rev/sec. If her initial moment of inertia was Ii =4.6 kg-m 2 what is her final moment of inertia If? A) 27.6 kg-m2 B) 2.76 kg-m 2 C) 0.77 kg-m 2 D) 0.17 kg-m 2 (13) A 15 gram paper clip is attached to the rim of a phonograph record with a radius of 30 cm 13) spinning at 3.5 rads/sec. What is the magnitude of the paper clip s angular momentum? A) kg-m 2 /s B) kg-m 2 /s C) kg-m 2 /s D) kg-m 2 /s (14) The entrance of a science museum features a funnel into which marbles are rolled one at 14) a time. The marbles circle the wall of the funnel, eventually spiraling down into the neck of the funnel. The internal radius of the funnel at the top is 0.54 m. At the bottom, the funnel s neck narrows to an internal radius of m. A kg marble begins rolling in a large circular orbit around the funnel s rim at 0.35 rev/s. If it continues moving in a roughly circular path, what will the marble s angular speed be as it passes through the neck of the funnel? A) 133 rads/s B) 525 rad/s C) 375 rads/s D) 400 rad/s (15) A 15.0 kg turntable with a radius of 25 cm is covered with a uniform layer of dry ice that 15) has a mass of 9.0 kg. The angular speed of the turntable and dry ice is initially 0.75 rads/s, but it increases as the dry ice evaporates. What is the angular speed of the turntable once all the dry ice has evaporated? A) 6.25 rads/s B) 1.2 rad/s C) 0.47 rads/s D) 18.0 rad/s

14 Page 4 (16) Calculate the angular momentum of Earth that arises from its spinning on its axis. 16) (Distance from Sun to Earth is 1.50 x m; Earth mass = 5.98 x kg; Sun mass = 1.99 x kg; Earth radius = 6.37 x 10 6 m; Sun s radius = 6.96 x 10 8 m) A) kg-m 2 /s B) kg-m 2 /s C) kg-m 2 /s D) kg-m 2 /s (17) Calculate the angular momentum of Earth that arises from its orbital motion about the sun. 17) (Distance from Sun to Earth is 1.50 x m; Earth mass = 5.98 x kg; Sun mass = 1.99 x kg; Earth radius = 6.37 x 10 6 m; Sun s radius = 6.96 x 10 8 m) A) kg-m 2 /s B) kg-m 2 /s C) kg-m 2 /s D) kg-m 2 /s (18) A woman sits on a spinning piano stool with her arms folded. When she extends her arms, 18) which of the following occurs? A) She increases her moment of inertia, thereby increasing her angular speed. B) She increases her moment of inertia, thereby decreasing her angular speed. C) She decreases her moment of inertia, thereby increasing her angular speed. D) She decreases her moment of inertia, thereby decreasing her angular speed. (19) A puck on a frictionless air-hockey table has a mass of 0.05 kg and is attached to a cord 19) passing through a hole in the table surface. The puck is originally revolving at a distance of 0.30 m from the hole, with an angular speed 2.50 rads/s. The cord is then pulled from below, shortening the radius of circle in which the puck revolves to 0.10 m. What is the puck s new angular velocity? A) 7.50 rads/s B) 8.33 rad/s C) 22.5 rads/s D) 27.8 rad/s (20) Suppose that our sun runs out of nuclear fuel and suddenly collapses to form a so-called 20) white dwarf, with a diameter equal to that of Earth. Assuming no mass loss, what would be the sun s new rotation period (time for one rotation), which is currently about 25 days. A) 2.25 days B) 1.65 hours C) 9.50 min D) 3.01 min

15 Name AP Physics Summer Work Universal Gravitation (1) The force of gravity is directly proportional to the radial distance between two objects. 1) (2) The value of the universal gravitation constant, G, was discovered by Newton. 2) (3) The universal gravitational constant, G, depends on the distance from the center of earth. 3) (4) The reason the force of gravity controls the motion of planets lies in the fact that the masses 4) involved are very large. (5) The force of gravity is inversely proportional to the radial distance squared between the two 5) objects. (6) If one were to halve the distance between the centers of two objects, the force of gravity 6) between the two objects would be multiplied by four. (7) The force of gravity exerted by the Earth on the Moon is greater than the Moon s 7) gravitational force on the Earth. (8) Who was the first scientist to see the connection between falling objects, projectiles and 8) satellites in orbit? A) Aristotle B) Galileo C) Sir Isaac Newton D) Copernicus (9) Why does the Earth exert enough gravitational force on our moon to keep it in orbit 9) about the Earth when the sun for our solar system is about a million times more massive than our Earth? A) The moon is pretty small compared to the Earth. B) The centripetal force exerted by the Sun is smaller. C) The Moon has a smaller mass density than the sun. D) The Moon is closer to Earth. (10) On Mars surface the robot Curiosity will weigh 1260 Newtons. If the radius of Mars is 10) 3400 km, what will Curiosity weigh 6800 km above the surface of Mars? A) 140 N B) 315 N C) 630 N D) 2520 N

16 Page 2 (11) By what factor would your weight change if the Earth s diameter were doubled and its mass 11) were also doubled? A) You would weigh one-fourth as much. B) You would weigh twice as much. C) You would weigh four times as much. D) You would weigh one-half as much. (12) If the gravitational forces of the sun on the planets suddenly disappeared in what kind of 12) paths would the planets move? A) The planets would spiral into the sun. B) The planets would fly off radially outward from the sun. C) The planets would fly directly toward the sun. D) The planets would fly off tangentially in straight line paths. (13) Which requires more fuel: sending a rocket from Earth to the Moon or sending the rocket 13) form the Moon to the Earth? A) It takes the same amount of fuel if they travel the same distance each way. B) It takes more fuel to go from the Earth to the Moon because you have to overcome a a greater gravitational force. C) It take more fuel to go from the Moon to the Earth because the Moon is not as massive. D) It takes more fuel to go from Earth to the Moon because the Earth has an atmosphere and the Moon does not. (14) If tides on Earth are caused by gravitational forces when would you expect to see the 14) highest tides? A) When the Moon and the Sun are on the same side of the Earth. B) When the Moon and the Sun are on opposite sides of the Earth. C) When the Sun and the Moon are at right angles to each other with respect to the Earth. D) It does not matter at all where the Moon and the Sun are with respect to the Earth (15) The strength of a gravitational field is sometimes written in terms of force on a single 15) kilogram of mass. In your Physics classroom the gravitational field strength is 9.8 N/kg. What would you expect the gravitational field strength to be one Earth radii above the Earth s surface? A) 4.9 N/kg B) 2.45 N/kg C) 6.53 N/kg D) 19.6 N/kg (16) If a box on the floor has a mass of 46 kilograms then the earth attracts that mass with a 16) force of A) 1 Newton B) 450 Newtons C) 4500 Newtons D) You cannot calculate the gravitational force without knowing the mass of the Earth.

17 Page 3 (17) A really dense planet has the same mass as the Earth but only one-tenth the radius. What 17) would Haley weigh on this planet if she weighs 400 Newtons on Earth? A) 4000 Newtons B) 40 Newtons C) 4 Newtons D) 40,000 Newtons (18) A 20 Newton force existed between two objects. If one object doubled in mass and the 18) other object tripled in mass while the distance between them halved what would be the new gravitational force between them? A) 120 Newtons B) 48 Newtons C) 60 Newtons D) 480 Newtons (19) If the gravitational field strength at the surface of one planet is 540 Newtons/ kilogram 19) what would the gravitational field strength be one planet diameter above the planet s surface? A) 270 Newtons/kilogram B) 180 Newtons/kilogram C) 60 Newtons/kilogram D) 90 Newtons/kilogram (20) The average distance between an electron and a proton in a hydrogen atom is m. 20) If the rest mass of an electron is given to be kg and the mass of the proton is given to be kg, what is the gravitational force between the two particles? (Note the universal gravitational constant, G = N m 2 /kg 2 ) A) Newtons B) Newtons C) Newtons D) Newtons (21) Calculate the force of gravity between Earth (Mass = kg) and the Moon (mass 21) = kg). The average distance between the Earth and Moon is m. A) N B) N C) N D) N (22) The mass of an electron is kg. The mass of a proton is kg. If the 22) gravitational force of attraction between an electron and a proton in a hydrogen atom is N, how far apart are the electron and proton? A) m B) m C) m D) m

18 Page 4 (23) There is a force on Earth that is directed toward the sun. 23) (24) Because Earth is "falling" around the sun, it will eventually crash into it. 24) (25) The force on a ball decreases as the ball moves farther from Earth. 25) (26) If Earth were its present size but twice as massive, we would weigh less. 26) (27) Because Earth has mass, it also has a gravitational field. 27) (28) Newton had the insight to see that the 28) A) force on the moon has the same nature as the force on an apple. B) moon always keeps one side toward Earth. C) moon is moving. D) moon orbits Earth. (29) Newton did not hypothesized that the moon 29) A) is a projectile. B) is falling around Earth. C) has tangential velocity that prevents it from falling into Earth. D) causes tides on Earth. (30) Newton reasoned that the gravitational attraction between Earth and the moon must be 30) A) directly proportional to distance. B) the same at all distances. C) reduced by distance. D) independent of distance. (31) If the mass of Earth increased, with no change in radius, your weight would 31) A) decrease. B) stay the same. C) increase also. (32) If the radius of Earth decreased, with no change in mass, your weight would 32) A) not change. B) decrease. C) increase. (33) A very massive object A and a less massive object B move toward each other under the 33) of mutual gravitation. Which force, if either is greater? A) The force on A B) The force on B C) Both forces are the same