Midterm Review. January 07, Grade:«11-12» Subject:Honors Physics. Date:«1/7-1/8 2015»

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1 Midterm Review 1 train moves at a constant velocity of 90 km/h. How far will it move in 0.25 h? Grade:«11-12» Subject:Honors Physics ate:«1/7-1/8 2015» 10 km 22.5 km 25 km 45 km 50 km 2 bicyclist moves at a constant speed of 6 m/s. How long it will take for the bicyclist to move 36 m? 3 s 6 s 12 s 9 s 18 s 3 The graph represents the relationship between velocity and time for an object moving in a straight line. What is the traveled distance of the object at 5 s? 10 m 15 m 20 m 48 m 56 m 4 Which of the following is true? 5 What is the velocity of the object? The object increases its velocity The object decreases its velocity The object s velocity stays unchanged The object stays at rest More information is required 2 m/s 4 m/s 6 m/s 8 m/s 10 m/s

2 6 The graph represents the position as a function of time of a moving object. What is the velocity of the object? 7 Starting from the origin, a person walks 8 km east during first day, and 5 km west the next day. What is the net displacement of the person from the initial point in two days? 5 m/s -5 m/s 10 m/s -10 m/s 0 m/s 6 km, east 3 km, east 10 km, west 5 km, west 9 km, east 8 n object moves with a constant acceleration of 6 m/s 2. Which of the following statements is true? 9 truck travels east with an increasing velocity. Which of the following is the correct direction of the car s acceleration? The object s velocity stays the same The object moves 6 m each second The object s acceleration increases by 6 m/s2 each second The object s acceleration decreases by 6 m/s2 each second the object s velocity increases by 6 m/s each second 10 motorbike travels east and begins to slow down before a traffic light. Which of the following is the correct direction of the motorbike s acceleration? 11 Which of the following is the velocity vs. time graph?

3 12 n object is released from rest and falls in the absence of air resistance. Which of the following is true about its motion? Its acceleration is Its acceleration is constant Its velocity is constant Its acceleration is increasing Its velocity is decreasing 13 package is dropped from an air balloon two times. In the first trial the distance between the balloon and the surface is H and in the second trial 4H. ompare the time it takes for the package to reach the surface in the second trial to that in the first trial? The time in the second trial is four times greater The time in the second trial is two times greater The time the same in both trials because it doesn t depend on height The time in the second trial is four times less The time in the second trial is two times less 14 Two baseballs are thrown from the roof of a house with the same initial speed, one is thrown up, and the other is down. ompare the speeds of the baseballs just before they hit the ground. The one thrown up moves faster because the initial velocity is up The one thrown down moves faster because the initial velocity is down They both move with the same speed The one thrown up moves faster because it has greater acceleration The one thrown down moves faster because it has greater acceleration 15 n archer practicing with an arrow bow shoots an arrow straight up two times. The first time the initial speed is v 0 and second time he increases the initial sped to 4v 0. How would you compare the maximum height in the first trial to that in the first trial? Two times greater Four times greater ight times greater Sixteen times greater The same 16 How far from the origin does the object move in first 10 s? 4 m 16 m 20 m 28 m 36 m 17 The position and the elapsed time of a motorbike are presented by the diagram. The motorbike starts from rest and accelerates at a constant rate. What is the acceleration of the motorbike? 0 m/s 2 2 m/s 2 4 m/s 2 6 m/s 2 8 m/s 2

4 18 In order for a rocket ship in deep space, far from any other objects, to move in a straight line with constant speed it must exert a net force that is 19 If a book on the dashboard of your car suddenly flies towards you, the forward velocity of the car must have proportional to its mass decreased proportional to its weight increased proportional to its velocity changed direction to the right become proportional to its displacement changed direction to the left 20 passenger standing in a moving bus, facing forward suddenly falls backward. This can be an indication which of the following? 21 net force F acts on a mass m and produces an acceleration a. What acceleration results if a net force 3F acts on mass 6m? The bus speeds The bus slows down The bus doesn t change its velocity The bus turns to the right The bus turns to the left a/2 8a 4a 2a a/4 22 car traveling at 40 m/s strikes a mosquito. Which of the following is the true statement? The force on the mosquito is greater than the force on the car The force on the mosquito is equal to the force on the car The force on the mosquito is smaller than the force on the car The damage to the mosquito is equal to the damage to the car 23 railroad wagon pushes down on a railroad with a force of 400 kn. Which of the following is the reaction force? The wagon pulls up the arth with 400 kn The wagon pushes down the railroad with 400 kn The railroad pushes up the wagon with 400 kn The buoyant force pushes up the wagon with 400 kn The wagon pushes down the arth with 400 kn None from the above

5 24 soccer player kicks a soccer ball with a force of 1300 N. The soccer ball hits the player with a force of 25 n elevator of mass M is pulled upwards by a cable; the elevator has a positive, but decreasing, velocity. What is the tension in the cable (neglecting the mass of the cable)? less than 1300 N exactly 1300 N more than 1300 N 0 N none from the above less than between and Mg equal to Mg greater than Mg 26 n elevator of mass M is pulled upwards at constant velocity by a cable. What is the tension in the cable (neglecting the mass of the cable)? 27 In the figure to the right, two boxes of masses m and 4m are in contact with each other on a frictionless surface. What is the force causing the acceleration of the more massive box? less than between and Mg equal to Mg greater than Mg 4F 3F/2 5F/4 4F/5 F/6 28 block of mass 4m can move without friction on a horizontal table. This block is attached to another block of mass m by a string that passes over a frictionless pulley. If the masses of the string and the pulley are negligible, what is the magnitude of the acceleration of the descending block? g/5 g/4 g/3 g/7 g/6 29 system of two blocks is accelerated by an applied force of magnitude F on the frictionless horizontal surface. The tension in the string between the blocks is: 3F 5F 3/8 F 1/3 F 1/5 F

6 30 car moves around a circular path of a constant radius at a constant speed. Which of the following statements is true? The car s velocity is constant The car s acceleration is constant The car s acceleration is The car s velocity is directed toward the center The car s acceleration is directed toward the center 31 small sphere is swung in a vertical circle. Which of the following combinations represents the direction of the velocity and acceleration at the point where the sphere is located? 32 small sphere is swung in a vertical circle. Which of the following combinations represents the direction of the velocity and acceleration at the point where the sphere is located? Midterm Review Part 2 Grade:«grade» Subject:Physics ate:«date» 1 n object experiences a uniform circular motion in a horizontal plane. The direction of the net force is: 2 boy stands at the edge of a rotating table. In order to keep him moving in a circular path the table applies a static friction force on the boy. Which of the following is the reaction force? The normal force on the boy The force of gravity exerted on the boy by arth The force of gravity exerted on arth by the boy The force exerted on the table by the boy that is directed straight down The static friction force exerted by the boy on the table

7 3 n object travels in a circular path of radius r at a constant speed v. What happens to the object s acceleration if the speed is doubled and the radius stays unchanged? 4 n object moves at a constant acceleration a in a circular path of radius r. Which of the following is the object s velocity? It doubles It quadruples It is cut to a half It is cut to a quarter Stays unchanged 5 n object of mass m moves at a constant speed v around a circular path of radius r. The net force applied to the object is F. What happens to the net force if speed is doubled and radius remains the same? 6 roller coaster car moves on a track with one section of vertical circular loop of radius R. When the car is at the top of the loop it just maintains contact with the track, what is the car s acceleration at this point? It doubles g upward It quadruples 0.5 g upward Stays the same Zero Is cut to one-half 0.5 g downward Is cut to one-quarter g downward 7 pilot performs a vertical maneuver around a circle with a radius R. When the airplane is at the lowest point of the circle pilot s weight is 6 mg. What is the acceleration at the lowest point? g 2 g 3 g 4 g 5 g 8 Two objects, one with a mass of m and one with a mass of 4m are attracted to each other by a gravitational force. If the force on 4m is F, what is the force on mass m in terms of F? 16F 4F F ¼ F 1/16 F

8 9 Two objects are attracted to each other by a gravitational force F. If one mass is doubled and the other is tripled without changing the distance, what is the new gravitational force between the objects in terms of F? 10 Two objects are attracted to each other by a gravitational force F. If the distance between the objects is doubled, what is the new gravitational force between the objects in terms of F? 4 F 9 F 6 F 1/9 F 1/6 F 4 F 9 F 16 F 1/9 F 1/4 F 11 Two objects are attracted to each other by a gravitational force F. If each mass is tripled and the distance between the objects is cut in half, what is the new gravitational force between the objects in terms of F? 12 hypothetical planet has a mass of four times that of the arth and radius of twice that of the arth? What is the acceleration due to gravity on the planet in terms of the acceleration on the arth? 24 F 36 F 16 F 1/16 F 1/24 F 13 block of mass m is pulled over a distance d by an applied force F which is directed in parallel to the displacement. How much work is done on the block by the force F? 14 block of mass m is moved over a distance d. n applied force F is directed perpendicularly to the block s displacement. How much work is done on the block by the force F? mfd Fd F/d -Fd mfd Fd F/d -Fd

9 15 truck driver is trying to push a loaded truck with an applied force. Unfortunately, his attempt was unsuccessful the truck stays stationary no matter how hard the driver pushes. How much work is done by the driver? Fd Fd 16 container with a mass of 5 kg is lifted to a height of 8 m. How much work is done by the gravitational force? lots -400 J Rawr -50J Zero 17 container with a mass of 5 kg is lifted to a height of 8 m and then returned back to the ground level. How much work is done by the gravitational force?.3215 J -400 J lots -50J 18 machine generates 2500 W of power in 1 min. What is the work done by the machine? 15 W 150 W 2500 W W W 19 car travels with a constant speed of 15 m/s. The car s engine produces a 4000 N pushing force in order to keep the speed constant. How much power is developed by the engine? 20 motorbike engine can develop a power of W in order to keep a constant velocity of 30 m/s. What is the pushing force? 3000 N 60 W 600 W 6000 W W N N 300 N 30 N W

10 21 cannon fires a cannonball and recoils backward. Which of the following statements is true about the cannon recoil? It happens because the energy of the system is conserved It happens because the energy of the system is increased It happens because the momentum of the system is not conserved It happens because the momentum of the system is conserved It happens because the momentum of the system is increased 22 n air balloon hovers at a certain altitude above the ground. pilot throws a sand bag down from the balloon. What is the direction of the balloon s velocity just after the bag was thrown? 23 What is the momentum of the cannon after firing a cannon ball with an initial momentum of 5,000 kg m/s to the right? 5,000 kg m/s to the right 5,000 kg m/s to the left 2,500 kg m/s to the right 2,500 kg m/s to the left 24 platform moves at a constant velocity on a horizontal surface. What happens to the velocity of the platform after a sudden rain falls down? It increases because the energy is conserved It decreases because the energy is conserved It remains constant because the momentum is conserved It increases because the momentum is conserved It decreases because the momentum is conserved 25 stationary skateboarder I with a mass of 50 kg pushes a stationary skateboarder II with a mass of 75 kg. fter the push the skateboarder II moves with a velocity of 2 m/s to the right. What is the velocity of the skateboarder I? 26 The force as a function of time is presented by the graph. What is the impulse exerted on the object during first five seconds? 3 m/s to the left 40 N s 2 m/s to the left 80 N s 1 m/s to the right 120 N s 3 m/s to the right 200 N s 2 m/s to the right 360 N s