Name: 1) 2) 3) Two students are pushing a car. What should be the angle of each student's arms with respect to the flat ground to maximize the horizontal component of the force? A) 90 B) 0 C) 30 D) 45 What is an essential characteristic of an object in equilibrium? A) zero kinetic energy B) zero velocity C) zero acceleration D) zero potential energy 2247-1 - Page 1 The diagram below shows a block on a horizontal frictionless surface. A 100.-newton force acts on the block at an angle of 30. above the horizontal. 4) 5) 6) What is the magnitude of force F if it establishes equilibrium? A) 86.6 N B) 50.0 N C) 187 N D) 100. N In which situation is the net force on the object equal to zero? A) an automobile braking to a stop B) a pitched baseball being hit by a bat C) a bicycle moving at constant speed on a straight, level road D) a satellite moving at constant speed around Earth in a circular orbit A man standing on a scale in an elevator notices that the scale reads 30 newtons greater than his normal weight. Which type of movement of the elevator could cause this greater-than-normal reading? A) accelerating upward B) accelerating downward C) moving downward at constant speed D) moving upward at constant speed The diagram below represents a 0.40-kilogram stone attached to a string. The stone is moving at a constant speed of 4.0 meters per second in a horizontal circle having a radius of 0.80 meter. 7) 8) 9) What is the magnitude of the centripetal acceleration of the stone? A) 0.0 m/s2 B) 2.0 m/s2 C) 20. m/s2 D) 5.0 m/s2 A high school physics student is sitting in a seat reading this question. The magnitude of the force with which the seat is pushing up on the student to support him is closest to A) 6,000 N B) 0 N C) 600 N D) 60 N A 1,200-kilogram car traveling at 10. meters per second hits a tree and is brought to rest in 0.10 second. What is the magnitude of the average force acting on the car to bring it to rest? A) 1.2 103 N B) 1.2 104 N C) 1.2 105 N D) 1.2 102 N A ball having mass m is struck by a bat having mass 9m. Compared to the magnitude of the force exerted by the bat on the ball, the magnitude of the force exerted by the ball on the bat is A) the same B) greater C) less
10) A constant unbalanced force is applied to an object for a period of time. Which graph best represents the acceleration of the object as a function of elapsed time? 2247-1 - Page 2 A) C) B) D) 11) 12) The force required to start an object sliding across a uniform horizontal surface is larger than the force required to keep the object sliding at a constant velocity. The magnitudes of the required forces are different in these situations because the force of kinetic friction A) decreases as the speed of the object relative to the surface increases B) increases as the speed of the object relative to the surface increases C) is less than the force of static friction D) is greater than the force of static friction The table below lists the coefficients of kinetic friction for four materials sliding over steel. 13) A 10.-kilogram block of each of these materials is pulled horizontally across a steel floor at constant velocity. Which block requires the smallest applied force to keep it moving at constant velocity? A) aluminum B) steel C) copper D) brass The diagram below represents a block sliding down an incline. 14) 15) Which vector best represents the frictional force acting on the block? A) A B) B C) C D) D If the magnitude of the gravitational force of Earth on the Moon is F, the magnitude of the gravitational force of the Moon on Earth is A) larger than F B) smaller than F C) equal to F A wooden block is at rest on a horizontal steel surface. If a 10.-newton force applied parallel to the surface is required to set the block in motion, how much force is required to keep the block moving at constant velocity? A) less than 10. N B) 10. N C) greater than 10. N
16) 2247-1 - Page 3 The graph below represents the relationship between gravitational force and mass for objects near the surface of Earth. 17) 18) What does the slope of the graph represent? A) acceleration due to gravity B) universal gravitational constant C) weight of objects D) momentum of objects The magnitude of the acceleration due to gravity on the surface of planet A is twice as great as on the surface of planet B. What is the ratio of the weight of mass X on the surface of planet A to its weight on the surface of planet B? A) 4:1 B) 1:4 C) 2:1 D) 1:2 The diagram below shows a force of magnitude F applied to a mass at angle relative to a horizontal frictionless surface. 19) As angle is increased, the horizontal acceleration of the mass A) decreases B) remains the same C) increases The diagram below shows a horizontal 8.0-newton force applied to a 4.0-kilogram block on a frictionless table. 20) 21) What is the magnitude of the block's acceleration? A) 9.8 m/s2 B) 32 m/s2 C) 2.0 m/s2 D) 0.50 m/s2 A spring scale reads 20. newtons as it pulls a 5.0-kilogram mass across a table. What is the magnitude of the force exerted by the mass on the spring scale? A) 4.0 N B) 5.0 N C) 20. N D) 49 N A 40.-kilogram mass is moving across a horizontal surface at 5.0 meters per second. What is the magnitude of the net force required to bring the mass to a stop in 8.0 seconds? A) 25 N B) 1.0 N C) 40. N D) 5.0 N
22) 2247-1 - Page 4 The diagram below shows a compressed spring between two carts initially at rest on a horizontal frictionless surface. Cart A has a mass of 2 kilograms and cart B has a mass of 1 kilogram. A string holds the carts together. 23) 24) 25) What occurs when the string is cut and the carts move apart? A) The magnitude of the impulse applied to cart A is twice the magnitude of the impulse applied to cart B. B) The length of time that the force acts on cart A is twice the length of time the force acts on cart B. C) The magnitude of the acceleration of cart A is one-half the magnitude of the acceleration of cart B. D) The magnitude of the force exerted on cart A is one-half the magnitude of the force exerted on cart B. A 1.5-kilogram lab cart is accelerated uniformly from rest to a speed of 2.0 meters per second in 0.50 second. What is the magnitude of the force producing this acceleration? A) 0.70 N B) 1.5 N C) 6.0 N D) 3.0 N A 50.-newton horizontal force is needed to keep an object weighing 500. newtons moving at a constant velocity of 2.0 meters per second across a horizontal surface. What is the magnitude of the frictional force acting on the object? A) 0 N B) 450. N C) 50. N D) 500. N Which graph best represents the relationship between acceleration due to gravity and mass for objects near the surface of Earth? [Neglect air resistance.] A) C) B) D) 26) 27) A net force of 25 newtons is applied horizontally to a 10.-kilogram block resting on a table. What is the magnitude of the acceleration of the block? A) 0.0 m/s2 B) 0.26 m/s2 C) 2.5 m/s2 D) 0.40 m/s2 A different force is applied to each of four 1-kilogram blocks to slide them across a uniform steel surface at constant speed as shown below. In which diagram is the coefficient of friction between the block and steel smallest? A) C) B) D) 28) A mosquito flying over a highway strikes the windshield of a moving truck. Compared to the magnitude of the force of the truck on the mosquito during the collision, the magnitude of the force of the mosquito on the truck is A) the same B) larger C) smaller
29) In the diagram below, a box is on a frictionless horizontal surface with forces F1 and F2 acting as shown. 2247-1 - Page 5 If the magnitude of F1 is greater than the magnitude of F2, then the box is 30) A) accelerating in the direction of F2 B) moving at constant speed in the direction of F2 C) accelerating in the direction of F1 D) moving at constant speed in the direction of F1 The diagram below shows a block sliding down a plane inclined at angle with the horizontal. 31) 32) As angle is increased, the coefficient of kinetic friction between the bottom surface of the block and the surface of the incline will A) increase B) decrease C) remain the same A net force of 10. newtons accelerates an object at 5.0 meters per second2. What net force would be required to accelerate the same object at 1.0 meter per second2? A) 2.0 N B) 1.0 N C) 50. N D) 5.0 N The diagram below shows a granite block being slid at constant speed across a horizontal concrete floor by a force parallel to the floor. Which pair of quantities could be used to determine the coefficient of friction for the granite on the concrete? A) frictional force and speed of the block B) frictional force and normal force on the block C) mass and speed of the block D) mass and normal force on the block
33) 2247-1 - Page 6 A 1.00 103-kilogram car is driven clockwise around a flat circular track of radius 25.0 meters. The speed of the car is a constant 5.00 meters per second. 34) 35) 36) 37) 38) What is the minimum friction force that must exist between the tires and the road to prevent the car from skidding as it rounds the curve? A) 1.00 103 N B) 1.25 105 N Which person has the greatest inertia? A) a 110-kg wrestler resting on a mat B) a 90-kg man walking at 2 m/s C) a 50-kg girl sprinting at 10 m/s D) a 70-kg long-distance runner traveling at 5 m/s C) 9.80 104 N D) 5.00 103 N What is the magnitude of the gravitational force between two 5.0-kilogram masses separated by a distance of 5.0 meters? A) 3.3 10-10 N B) 1.3 10-11 N C) 5.0 100 N D) 6.7 10-11 N An object weighs 100. newtons on Earth's surface. When it is moved to a point one Earth radius above Earth's surface, it will weigh A) 400. N B) 100. N C) 25.0 N D) 50.0 N What is the speed of a 1.0 103-kilogram car that has a momentum of 2.0 104 kilogram meters per second east? A) 1.0 104 m/s B) 2.0 107 m/s C) 5.0 10-2 m/s D) 2.0 101 m/s A 0.050-kilogram bullet is fired from a 4.0-kilogram rifle that is initially at rest. If the bullet leaves the rifle with momentum having a magnitude of 20. kilogram meters per second, what will be the magnitude of the momentum of the rifle's recoil? A) 0.25 kg m/s B) 1,600 kg m/s C) 20. kg m/s D) 80. kg m/s
39) 2247-1 - Page 7 The diagram below shows a 0.1-kilogram apple attached to a branch of a tree 2 meters above a spring on the ground below. The apple falls and hits the spring, compressing it 0.1 meter from its rest position. If all of the gravitational potential energy of the apple on the tree is transferred to the spring when it is compressed, what is the spring constant of this spring? A) 40 N/m B) 10 N/m C) 400 N/m D) 100 N/m 40) A bullet traveling at 5.0 102 meters per second is brought to rest by an impulse of 50. newton seconds. What is the mass of the bullet? A) 1.0 101 kg B) 2.5 104 kg C) 1.0 10-1 kg D) 1.0 10-2 kg