AP Physics II Summer Packet

Transcription

1 Name: AP Physics II Summer Packet Date: Period: Complete this packet over the summer, it is to be turned it within the first week of school. Show all work were needed. Feel free to use additional scratch paper if necessary Motion 1) In an experiment two baseballs are dropped from the top of a tall building. When the first baseball is dropped the timer is started. After 1.0 s the second baseball is dropped. Assuming air resistance can be neglected, which of the following will be true? A. The difference in velocity between the two baseballs decreases as they fall B. The difference in velocity between the two baseballs remains constant as they fall C. The distance between the baseballs decreases as they fall D. The distance between the baseballs stays constant as they fall 2) A Physics teacher releases a lab cart from the top of an incline as shown in the figure. The teacher asks the students to predict what the position-time graph for the horizontal motion of the cart will look like. Four students give their answers shown below. Which student predicted the motion most accurately?

2 3) The figure shows the velocity-time graph of an object. Which of the following statements is consistent with the motion of the object. A. The object is moving horizontally and then descends a steep slope. B. The object passes through the origin at 2 seconds. C. Assuming the object started at position x = 0, it will pass through the origin between 3 s and 4 s D. The acceleration of the object is not constant, first the object accelerates in the positive direction and then accelerates in the negative direction. 4) Students track the motion of a car moving along horizontally from left to right. By placing a dot at the position of the front of the car every 2 seconds, they produce the motion diagram displayed above. Which of the following velocity-time graphs is consistent with the motion diagram? 5) A car starts at rest from the top of a long downward sloping road. The driver lets the car coast down to the bottom of the road, then checks the car s travel computer. The computer indicates that the car traveled a total distance of 1.6 km at an average speed of 38 km/hr. Assuming a constant sloping road, what was the acceleration of the car? A. 450 km/hr 2 B. 900 km/hr 2 C km/hr 2 D. More information is needed to calculate the acceleration of the car.

3 Forces and Newton s Laws 6) A physics student takes a video of a car rolling down a hill. Using a motion tracking app, the student places a dot on the front of the car for every frame in the video and produces the motion diagram shown in the picture above. Which of the following is correct for the situation shown in the motion diagram? A. There must be a net force acting on the car. B. Gravity from the Earth is the largest force acting on the car. C. The normal force acting on the car from the road is equal to the weight of the car. D. Friction between the car and the road is negligible. 7) A baseball player is idly tossing a ball straight up and catching the ball when it falls back down. Which diagram correctly depicts the forces acting on the ball while the ball is descending and being brought to rest by the player s hand? 8) A constant force F is applied to three blocks placed adjacent to each on a horizontal surface as shown in the figure. Which of the following statements is correct? A. The acceleration of all the blocks will be equal to! " B. The acceleration of each block will vary due to the different masses of each block. C. The net force acting on each block will be the same. D. The net force acting on the block 3m is the largest.

4 9) A wagon is accelerated to the right by a force F along the handle as shown in the figure. Let F N be the normal force between the wagon and the ground, F f be the frictional force between the ground and the wagon, and F g be the gravitational force between the wagon and the Earth. Which of the following statements about the relationships between the forces are correct? Select two answers. A. Fcosθ > F ) B. mg > F, C. F ) = μmg D. Fcosθ < ma 10) A net force is applied to an object as a function of time as shown in the figure. Which of the following motion graphs are consistent with the force-time graph?

5 Collisions: Impulse and Momentum 11) Two spheres traveling in opposite directions collide head on as shown. The graph shows the force between the spheres during the collision. The velocity of the 10 kg sphere after the collision is A. To the left at 1 m/s B. To the left at 1.75 m/s C. To the left at 4 m/s D. To the right at 1.75 m/s 12) A skateboard rolls under a tree at a constant velocity when a cat drops out of the tree vertically onto it. The skateboard & cat move off together. Which of the following statements is correct? A. The skateboard speeds up as the cat adds kinetic energy to the system. B. The skateboard speeds up as the cat adds vertical momentum to the system. C. The skateboard continues moving at the same speed as the cat and skateboard exert equal and opposite forces on each other which cancel out during the collision. D. The skateboard slows down due to the added mass of the cat to the horizontally moving skateboard. 13) A father and child are standing facing each other on an ice skating rink as shown. The father has about twice the mass of the child. They push against each other which causes them to glide apart. Which of the following statements are correct? Select two answers. A. The center of mass of the system consisting of the father and the child remains stationary as the two glide apart. B. The center of mass of the system consisting of the father and the child moves in the direction of the father as the two glide apart. C. As they glide apart, the kinetic energy of the father is equal to the kinetic energy of the child. D. As the two push against each other, the acceleration of the father is approximately half that of the child.

6 14) A physics student is given a velocity-time graph that shows the interaction of two lab carts as they collide while traveling on a long horizontal track. See figure. The two lab carts are labeled A and B. What can the student determine based on the information in this graph? A. The change in momentum of the two carts in not the same. B. The mass of cart A is less the mass of cart B. C. This is a perfectly elastic collision. D. Both carts change direction in the collision. 15) Two identical toy cars are placed on a horizontal table. The first car is hit from behind by a lump of clay that sticks to the back of the car causing it to move forward with a velocity v 1. The second car is hit from behind by a ball that bounces directly back off the car causing the car to move forward with a velocity v 2. See the figure above. Assuming that the clay and ball have the same initial velocity and the same mass, which statement best describes the final velocities of the cars v 1 and v 2? A. v 1 > v 2 because the clay imparts all of its momentum to the car. B. v 1 > v 2 because the ball impart only part of its momentum to the car. C. v 1 < v 2 because the ball imparts more momentum to the car. D. v 1 < v 2 because the ball and car have a perfectly elastic collision. Work and Energy 16) A 80 kg rollercoaster car traveling 10 m/s passes over the crest of a 40 m high hill as shown in the figure. The speed of the car at the bottom of the hill is 24 m/s. The mechanical energy lost to friction is most nearly A. 60 J B. 1,000 J C. 5,000 J D. 13,000J

7 17) Engineers are working on a new method for launching supplies to the International Space Station (ISS). This method consists of using a long cannon that shoots a capsule directly to the ISS where is will be retrieved and the supplies unloaded from the capsule. The length of this launch cannon is x f as seen in the figure. By using different propulsion fuels in the cannon, engineers can produce different force profiles on the capsule during launch as seen in the following graphs. The maximum force in each case is F max. Which force distribution will produce the greatest launch velocity of the supply capsule during launch? x f 18) A block moving at a velocity of 6 m/s, slides up a curved ramp to a stop 1.4 m above its original level. Which of the following best explains why the block stops moving at 1.4 m? A. All of the block s initial kinetic energy is converted into gravitational potential energy when the block stops. B. Negative work done by gravity and friction reduce the initial kinetic energy of the block to zero. C. The gravitational force from the Earth on the block brings the block to a stop. D. Friction between the block and the ramp causes the block to slow down and stop. m 19)

8 19) A toy car rolls off a countertop and falls to the floor as shown if the figure. Letting the floor be the vertical location of y = 0, which of the following graphs gives an accurate representation of the car-earth gravitational potential energy and kinetic energy of the car as a function of vertical location y? A) B) C) D) 20) Two blocks, A and B, sit at the top of identical frictionless inclines. The mass of block A is three times that of block B. The blocks are each released from rest and slide down the incline to the bottom. Which of the following correctly gives the relationships between the velocities and kinetic energies of the blocks when the reach the bottom of the incline? A. v A = v B and K A = K B B. v A = v B and K A > K B C. v A > v B and K A = K B D. v A > v B and K A > K B

9 Rotation 21) An ice skater is spinning on frictionless ice with her arms spread outward from her body. Her initial rotational velocity is w. The skater then moves her arms inward toward her body. How does the final rotational velocity and rotational inertia of the skater compare to the initial values? Rotational velocity Rotational inertia A. Remains constant Remains constant B. Decreases Decreases C. Remains constant Decreases D. Increases Decreases 22) A child stands on a rotating platform at point A as shown in the figure. The platform is rotating at a constant rate of ω when the child begins walking along the radius of the platform to point B. Which of the following statements explains the changes in the rotational velocity of the platform? A. The rotational velocity will increase because the child will be pushing on the platform with their feet which produces a torque which increases the rotation rate. B. The rotational velocity will remain the same because the child is walking directly along the radius and not producing a torque on the rotating platform. C. The rotational velocity will remain the same because there are no external forces acting on the child/platform system. D. The rotational velocity will decrease because the rotational inertia of the child/platform system has increased. 23) A thin hexagon shaped board is nailed through its center to the top of a horizontal table such that it is free to rotate. Four forces are applied to the board as shown in a top view of the board in the figure. The net torque on the board 2 N Top View 4 N A. Is clockwise B. Is counterclockwise C. Is zero D. Cannot be determined without knowing the dimensions of the board. 2 N 4 N

10 24) A block of mass m, and a sphere of mass m with radius R, are propelled up inclines of the same shape with identical initial velocities v. The block moves up a frictionless inline while the sphere s incline has enough friction so that the sphere rolls without slipping. Which of the following statements is correct concerning the velocities of the block and sphere when both have traveled a height h up their respective inclines? A. Friction causes the sphere to lose energy and to have a smaller velocity at h. B. Because both start with the same total energy and will have the same velocity at h. C. Both gain the same gravitational potential energy moving up the incline and will have the same velocity at h. D. Because the sphere has rotational kinetic energy, it will have a larger velocity at h. 25) An amusement park ride called The Giant Swings consists of seats suspended by chains from a platform. After the passengers are secured in their seats, the platform rotates and the passengers swing outward as they move around in a horizontal circle at a constant speed. While the ride is in operation, which of the following statements is correct? Select two answers. A. There is a net force away from the center of the ride that causes the passengers to swing outward while moving abound the circular path. B. The tension in the chain is greater than the weight of the passenger/swing. C. The velocity of the passengers is constantly changing as they go around the circle. D. The passengers are accelerating in the direction of the tension force. 26) A yo-yo is spinning counter clockwise on the end of its string in a vertical circle. When the yo-yo is half way between the highest and lowest point as shown, the direction of its acceleration is Rotation direction A. B. Circular path of yo-yo C. D.

11 Gravitation 27) Which of the following statements explain why Mars takes 687 days to orbit the Sun while the Earth only takes 365 days. Select two answers. A. Earth and Mars have different orbital radii B. The Earth has a larger mass than Mars C. Mars has an orbit that is elliptical D. The Earth has a larger centripetal acceleration 28) A rocket is launched from the surface of the moon on a return trip to Earth. If the rocket maintains a constant trust F T and mass m during its flight. When the rocket is one Moon radius about the surface, its acceleration will be A. Decreasing because the rocket no longer has the surface of the moon to push against. B. Remains the same because the rocket mass and thrust are constant. C. Increasing because the gravitational pull of the Moon is decreasing. D. Increasing because the gravitational pull of the Earth is increasing. 29) A satellite is in circular orbit around the Earth. What information is needed to determine the speed the satellite? Select two answers. A. The mass of the satellite B. The mass of the Earth C. The radius of the Earth D. The radius of the orbit 30) Pluto is in an elliptical orbit around the Sun. Moving from the aphelion A to the perihelion P points of its orbit, which of the following quantities increases for Pluto? Select two answers. A. Mechanical energy B. Angular momentum C. Linear momentum D. Gravitational force

12 31) An astronomer approximates the gravitational acceleration of Jupiter to be 2.5g E near the cloud top of the planet and its diameter to be 11D E, where g E and D E are the gravitational acceleration and diameters of Earth. From this information the astronomer estimates the density of Jupiter ρ Jupiter to be A ρ Earth B. 2.5 ρ Earth C ρ Earth D. 303 ρ Earth

13 Free Response A space probe is sent on a mission to map out the gravitational field intensity in the vicinity of a satellite of planet X. Some of the data collected is shown in the chart below: Distance to satellite ( 10 6 m) Field intensity (N/kg) (a) On the axes below, plot the gravitational field intensity, g, vs. the distance, R, to the satellite. (b) Draw in the appropriate best t line or curve. (c) Using the best t, what distance corresponds to a field intensity of 2.1 N/kg? (d) In order to determine the mass of the satellite, a plot of field intensity vs. 1/R 2 can be utilized. Fill in the appropriate values for 1/R 2 in the chart below.

14 (d) In order to determine the mass of the satellite, a plot of eld intensity vs. 1/R 2 can be utilized. Fill in the appropriate values for 1/R 2 in the chart below. 1/R 2 (1/m 2 ) eld intensity (N/kg) (e) On the axes below plot gravitational field intensity, g, vs. 1/R 2. (f ) Use the plot and best t to determine the mass of the satellite.