AP Physics Semester 1
An object is sliding to the right along a straight line on a horizontal surface. The graph shows the object's velocity as a function of time. What is the object's displacement during the time depicted in the graph? A. 0 m B. 1 m C. 8 m D. 16 m
A. 0 m
An object is sliding to the right along a straight line on a horizontal surface. The graph shows the object's velocity as a function of time. What is the object's displacement during the time depicted in the graph? A. 0m B. 1m C. 8m D. 16m
A. 0m
The graph above shows velocity v as a function of time t for a 0.50 kg object traveling along a straight line. The graph has three segments labeled 1, 2, and 3. A rope exerts a constant force of magnitude FT on the object along its direction of motion the whole time. During segment 2 only, a frictional force of magnitude Ff is also exerted on the object. Which of the following correctly ranks the displacement ∆x for the three segments of the object's motion? A. ∆x3 > ∆x2 > ∆x1 > 0 B. ∆x1 = ∆x2 = ∆x3 > 0 C. (∆x1 = ∆x3) > ∆x2 > 0 D. (∆x1 = ∆x3) > 0 > ∆x2
A. ∆x3 > ∆x2 > ∆x1 > 0
The graph above represents position x versus time t for an object being acted on by a constant force. The average speed during the interval between 1 s and 2 s is most nearly: A. 2 m/s B. 4 m/s C. 5 m/s D. 6 m/s E. 8 m/s
D. 6 m/s
A comet passes by a planet with a speed vo such that the comet travels in a straight line at the instant shown in the figure. The comet's tangential acceleration, centripetal acceleration, and force due to gravity from the planet at this location are provided in the table. Astronomers observe that the comet continues to travel in a nearly straight line, even though calculations show that the gravitational force exerted by the planet should cause the comet to move in a circular orbit. Why does the comet not travel in a circular path around the planet after the instant shown in the figure? Chart: Tangential Acceleration (m/s^2) = 0; Centripetal Acceleration (m/s^2) = 0; Force Due to Gravity on Comet from Planet (N) = 1.67 x 10^11 A. The comet is too far away to travel in a circular path around the planet. B. The planet's gravitational force is not strong enough to cause the comet to have a centripetal acceleration. C. The comet's inertia is so great that the direction of the comet cannot be changed by the gravitational force exerted by the planet. D. There must be another object such that the gravitational forced exerted on the comet are balanced at this location.
D. There must be another object such that the gravitational forced exerted on the comet are balanced at this location.
An object has a weight W when it is on the surface of a planet of radius R. What will be the gravitational force on the object after it has been moved to a distance of 4R from the center of the planet? A. 16W B. 4W C. W D. 1/4 W E. 1/16 W
E. 1/16 W
A rock of mass m is thrown horizontally off a building from a height h, as shown above. The speed of the rock as it leaves the thrower's hand at the edge of the building is vo. How much time does it take the rock to travel from the edge of the building to the ground? A. sqrt(hvo) B. h/vo C. hvo/g D. 2h/g E. sqrt(2h/g)
E. sqrt(2h/g)
A student wants to approximate the amount of work that the force due to gravity does on the student as the student walks up a set of stairs. Which of the following measurements must the student collect in order to approximate the amount of work done by Earth on the student? Select two answers. A. The mass of the student. B. The angle between the inclined portion of the stairs and the horizontal. C. The total inclined length of the stairs. D. The final vertical height above the initial vertical position.
A. The mass of the student. D. The final vertical height above the initial vertical position.
While traveling in its elliptical orbit around the Sun, Mars gains speed during the part of the orbit where it is getting closer to the Sun. Which of the following can be used to explain this gain in speed? A. As Mars gets closer to the Sun, the Mars-Sun system loses potential energy and Mars gains kinetic energy. B. A component of the gravitational force exerted on Mars is perpendicular to the direction of motion, causing an acceleration and hence a gain in speed along that direction. C. The torque exerted on Mars by the Sun during this segment of the orbit increases the Mars-Sun system's angular momentum. D. The centripetal force exerted on Mars is greater than the gravitational force during this segment of the orbit, causing Mars to gain speed as it gets closer to the Sun.
A. As Mars gets closer to the Sun, the Mars-Sun system loses potential energy and Mars gains kinetic energy.
A student conducts an experiment in which an object is released from rest above a motion detector so that data can be collected about the object's motion as the object falls to the ground. The experiment is conducted near Earth's surface. All frictional forces are considered to be negligible unless otherwise stated. The student collects the data necessary to graph the object's kinetic energy as a function of time, as shown. Which of the following graphs represents the sum of the kinetic energy K and gravitational potential energy Ug of the object-Earth system as a function of time? A. Constant; flat, horizontal line B. Exponentially decreasing curve C. Exponentially increasing curve D. Increasing curve, flattens around 2500
A. Constant; flat, horizontal line
An object slides across a horizontal surface such that it slows down due to the force of friction that is exerted on the object. The object and the direction of its displacement are shown in the figure. Which of the following free-body diagrams could represent the forces that are exerted on the object? A. Gravity = Normal force with little friction pointing left B. Normal force > gravity and a lot of friction pointing left C. Gravity > normal force and a lot of friction pointing left D. Gravity = Normal Force and little friction pointing right
A. Gravity = Normal force with little friction pointing left
The figure above represents the orbits of two planets of equal mass that orbit their star in the counterclockwise direction as a double-planet system. From the point of view of an observer on either planet, the planets appear to orbit each other while also orbiting the star. The dots on the orbits represent the position of the planets at time t0, and X is the position of their center of mass at that time. Which of the following arrows best represents the acceleration of the center of mass of the double-planet system when it is at point X ? A. Pointing down slightly left B. Pointing left, slightly downward C. Pointing left and upward D. Pointing right and upward
A. Pointing down slightly left
A rocket is continuously firing its engines as it accelerates away from Earth. For the first kilometer of its ascent, the mass of fuel ejected is small compared to the mass of the rocket. For this distance, which of the following indicates the changes, if any, in the kinetic energy of the rocket, the gravitational potential energy of the Earth-rocket system, and the mechanical energy of the Earth-rocket system? A. Rocket Kinetic Energy: Increasing; System Gravitational Potential Energy: Increasing; System Mechanical Energy: Increasing B. Rocket Kinetic Energy: Increasing; System Gravitational Potential Energy: Increasing; System Mechanical Energy: Constant C. Rocket Kinetic Energy: Increasing; System Gravitational Potential Energy: Decreasing; System Mechanical Energy: Decreasing D. Rocket Kinetic Energy: Decreasing; System Gravitational Potential Energy: Increasing; System Mechanical Energy: Constant
A. Rocket Kinetic Energy: Increasing; System Gravitational Potential Energy: Increasing; System Mechanical Energy: Increasing
Planet 1 orbits Star 1 and Planet 2 orbits Star 2 in circular orbits of the same radius. However, the orbital period of Planet 1 is longer than the orbital period of Planet 2. What could explain this? A. Star 1 has less mass than Star 2 B. Star 1 has more mass than Star 2 C. Planet 1 has less mass than Planet 2 D. Planet 1 has more mass than Planet 2 E. The masses of the planets are much less than the masses of the stars
A. Star 1 has less mass than Star 2
An object attached to one end of a string moves in a circle at constant speed. Which of the following is correct? A. The object is accelerating as it moves. B. The object's velocity is the same as its speed. C. The object does not require a force to keep its state of circular motion. D. If the string breaks, the object will keep its circular motion. E. If the string breaks, the object will move radially away from the center of the circle.
A. The object is accelerating as it moves.
A ball is tossed straight up and later returns to the point from which it was launched. If the ball is subject to air resistance as well as gravity, which of the following statements is correct? A. The speed at which the ball returns to the point of launch is less than its speed when it was initially launched, B. The time for the ball to fall is the same as the time for the ball to rise. C. The force of air resistance is directed down-ward both when the ball is rising and when it is falling. D. The net work by air resistance on the ball during its flight is zero. E. The net work done by gravity on the ball during its flight is greater than zero.
A. The speed at which the ball returns to the point of launch is less than its speed when it was initially launched,
A block of mass M is released from rest at point 1, as shown in the figure. The block slides without frictional forces along the circular arc but encounters frictional forces as soon as it reaches the horizontal portion of the track at point 2. The block travels a distance D along the horizontal track before coming to rest at point 3. Consider the block-Earth system. In terms of the mechanical energy of the system, which of the following claims is correct, and why? A. The system is open, because there is a net force exerted on the block. B. The system is open, because the block's velocity is zero at points 1 and 3. C. The system is closed, because there is a net force exerted on the block. D. The system is closed, because the block's velocity is zero at points 1 and 3.
A. The system is open, because there is a net force exerted on the block.
A box is given a sudden push up a ramp. Friction between the box and the ramp is not negligible. Which of the following diagrams best represents the directions of the actual forces acting on the box as it moves upward after the push? (all images are diagonal) A. arrow pointing left, parallel to the surface; arrow pointing up, perpendicular to the surface; arrow down, directly downward B. arrow pointing left, parallel to the surface; arrow pointing right, parallel to the surface; arrow pointing up, perpendicular to the surface; arrow pointing down, directly downward C. arrow pointing right, parallel to the surface; arrow pointing up, perpendicular to the surface; arrow pointing down, directly downward D. arrows left and right, parallel to the surface, arrows up and down, perpendicular to the surface E. arrow pointing right, parallel to the surface; arrows up and down, perpendicular to the surface
A. arrow pointing left, parallel to the surface; arrow pointing up, perpendicular to the surface; arrow down, directly downward
Two blocks of masses 1.0 kg and 2.0 kg, respectively, are pushed by a constant applied force F across a horizontal frictionless table with constant acceleration such that the blocks remain in contact with each other, as shown above. The 1.0 kg block pushes the 2.0 kg block with a force of 2.0 N. The acceleration of the two blocks is A. 0 B. 1.0 m/s^2 C. 1.5 m/s^2 D. 2.0 m/s^2 E. 3.0 m/s^2
B. 1.0 m/s^2
A 50 kg athlete running at speed v grabs a light rope that hangs from a 10-meter-high platform and swings to a maximum of 1.8 m above the ground. Later, a 100 kg athlete, running at the same speed, grabs a similar rope hanging from a 5-meter-high platform. What is the maximum height to which the 100 kg athlete swings? A. 0.9 m B. 1.8 m C. 2.5 m D. 3.6 m
B. 1.8 m
An object is thrown with a horizontal velocity of 20 m/s from a cliff that is 125 m above level ground. If air resistance is negligible, the time that it takes the object to fall to the ground from the cliff is most nearly... A. 3s B. 5s C. 6s D. 12s E. 25s
B. 5s
One end of a string is attached to a vertical pole with the other end of the string attached to a ball that swings in a horizontal circular path, as shown. Which of the following free body diagrams represents the forces exerted on the ball? A. Arrow to the left, and arrow downward B. Arrow downward and diagonally to the left and upward (northwest if comparing to a compass) C. Arrow up and down, arrow to the left D. Arrow up and down, and diagonally to the left and upward (northwest)
B. Arrow downward and diagonally to the left and upward (northwest if comparing to a compass)
An object begins at position x = 0 and moves one-dimensionally along the x-axis with a velocity v expressed as a function of time t according to the graph above. At what time does the object pass through x = 0 again? A. Between 10 s and 20 s B. Between 20 s and 30 s C. At 30 s exactly D. Between 30 s and 40 s E. After 40 s
B. Between 20 s and 30 s
Blocks A and B, of masses m and 2m, respectively, are connected by a light string and pulled across a surface of negligible friction with a constant force F1, as shown above. The acceleration of the blocks is a. The force of the string pulling block B forward has magnitude F2. Which of the following claims correctly describes the relationship between the magnitude of the forces acting on the blocks? A. F1 is equal to F2 B. F1 is greater than F2 C. F2 is equal to 3ma D. F2 is greater than 3ma
B. F1 is greater than F2
A student wants to launch a toy dart toward a target that hangs from a light string. At time t=0, the dart is launched with an initial speed v0 at an angle θ0 above the horizontal ground. At the instant the dart is launched, the string is cut such that the target begins to fall straight down. The positive horizontal direction is considered to be to the right, and the positive vertical direction is considered to be up. A student makes the necessary measurements to create the graph shown, which represents the vertical component of the velocity as a function of time for the dart and for the target from t=0 until the instant the dart hits the target. At t=0, the target is a vertical distance h above the dart. The curves for the dart and the target each have the same area between them and the horizontal axis. Both curves also have the same slope. Which of the following is the best method to determine the distance h from the graph? A. Find the area under the curve for the dart's data. B. Find twice the area under the curve for the dart's data. C. Find the slope of the curve for the dart's data. D. Find twice the slope of the curve for the dart's data.
B. Find twice the area under the curve for the dart's data.
Object A is released from rest at height h. At the same instant, object B is thrown downward from the same location. Which of the following graphs of speed of v as a function of time t is correct for the two objects? (These are descriptions of graphs, I can't add pictures :/ ) A. Lines B and A emerging from origin of the graph B. Lines B and A are parallel; line B at a higher starting point than line A which starts at the origin C. Line A starts at the origin; Line B starts above Line A on the y-axis with a steeper incline D. Line A starts at the origin; Line B starts above Line A on the y-axis with a shorter incline E. Line A starts at the origin, Line be inclines at a faster rate on a different x-axis
B. Lines B and A are parallel; line B at a higher starting point than line A which starts at the origin
A kitten sits in a lightweight basket near the edge of a table. A person accidentally knocks the basket off the table. As the kitten and basket fall, the kitten rolls, turns, kicks, and catches the basket in its claws. The basket lands on the floor with the kitten safely inside. If air resistance is negligible, what is the acceleration of the kitten-basket system while the kitten and basket are in midair? A. The acceleration is directed downward with magnitude less than g because the basket is light. B. The acceleration is directed downward with magnitude equal to g because the system is a projectile. C. The acceleration fluctuates because of the rolling, turning, and kicking motion of the kitten. D. The acceleration cannot be determined without knowing how hard the basket is pushed.
B. The acceleration is directed downward with magnitude equal to g because the system is a projectile.
A planet travels in an elliptical path around a star, as shown in the figure. As the planet gets closer to the star, the gravitational force that the star exerts on the planet increases. Which statement of reasoning best supports and correctly identifies what happens to the magnitude of the force that the planet exerts on the star as the planet gets closer to the star? A. The force remains constant because the mass of the planet remains constant. B. The force increases because it is part of a Newton's third law pair of forces with the force that the star exerts on the planet. C. The force decreases because the planet increases its speed as it gets closer to the star. D. The force fluctuates such that it increases and decreases because the planet does not travel in a perfectly circular path.
B. The force increases because it is part of a Newton's third law pair of forces with the force that the star exerts on the planet.
A cart of mass m is moving with speed vv on a smooth track when it encounters a vertical loop of radius R, as shown above. The cart moves along the inside of the entire loop without leaving the track. All frictional forces are negligible. Which of the following must be true for the cart to remain on the track when it is at point P? A. The net force exerted on the car must be less than the force that the track exerts on the cart. B. The net force exerted on the cart must be equal to or greater than the weight of the cart. C. The track must exert an upward force on the cart to prevent it from falling. D. The track must exert a force on the cart that is equal to the weight of the cart.
B. The net force exerted on the cart must be equal to or greater than the weight of the cart.
A crate is on a horizontal frictionless surface. A force of magnitude F is exerted on the crate at an angle θ to the horizontal, as shown in the figure above, causing the crate to slide to the right. The surface exerts a normal force of magnitude FN on the crate. As the crate slides a distance d, it gains an amount of kinetic energy ∆K. While F is kept constant, the angle θ is now doubled but is still less than 90 degrees. Assume the crate remains in contact with the surface. As the crate slides a distance d, how does the new gain in kinetic energy compare to ∆K? A. The new gain is greater than ∆K B. The new gain is less than ∆K C. The new gain is equal to ∆K D. The new gain is greater or less than ∆K depending on the value of θ
B. The new gain is less than ∆K
A crate is on a horizontal frictionless surface. A force of magnitude F is exerted on the crate at an angle θ to the horizontal, as shown in the figure above, causing the crate to slide to the right. The surface exerts a normal force of magnitude FN on the crate. As the crate slides a distance d, it gains an amount of kinetic energy ∆K. While F is kept constant, the angle θ is now doubled but is still less than 90o. Assume the crate remains in contact with the surface. A. The new normal force is greater than Fn B. The new normal force is less than Fn C. The new normal force is equal to Fn D. The new normal force is greater or less than Fn depending on the value of theta
B. The new normal force is less than Fn
A student drops a rock from the top of a cliff such that the rock falls downward toward Earth's surface in the absence of air resistance. The downward direction is considered to be the positive direction. The graph shows the rock's velocity as a function of time. Which of the following methods should be used to determine the total distance traveled by the rock after 4s ? A. Use the maximum value of the curve, as it states that the rock traveled 40 meters in 1 second, which means that the rock traveled 160 meters in total. B. Use the area under the curve, as it states that the rock traveled 80 meters in total. C. Use the slope of the curve, as it states that the rock traveled 10 m/s in 1 second, which means that the rock traveled 40 meters in total. D. The answer could not be determined unless a graph of the object's position as a function of time is given.
B. Use the area under the curve, as it states that the rock traveled 80 meters in total.
Two students want to determine the speed at which a ball is released when thrown vertically upward into the air. One student throws the ball into the air while the other student measures the total time that the ball is in the air. The students use a meterstick to measure the release height of the ball. Which of the following equations should the students use to determine the speed at which the ball was released? A. Use y=y0 + vy0t + 1/2ayt^2 from the moment in time in which the ball was released to the moment in time in which the ball reaches its highest point. B. Use y=y0 + vy0t + 1/2ayt^2 from the moment in time in which the ball was released to the moment in time in which the ball hits the ground. C. v^2y = v^2y0 +2a(y-y0) from the moment in time which the ball was released to the moment in time in which the ball reaches its highest point. D. v^2y = v^2y0 +2a(y-y0) from the moment in time in which the ball was released to the moment in time in which the ball hits the ground.
B. Use y=y0 + vy0t + 1/2ayt^2 from the moment in time in which the ball was released to the moment in time in which the ball hits the ground.
A ball of mass M swings in a horizontal circle at the end of a string of radius R at a constant tangential speed v0. A student gradually pulls the string inward such that the radius of the circle decreases while keeping the tangential speed v0 of the ball constant, as shown above. Which of the following graphs best represents the acceleration a of the ball as a function of time t? A. constant (flat line) B. exponentially increasing (curve upward) C. decreasing (curve downward, flattens near 0) D. exponentially decreasing (curve downward to infinity)
B. exponentially increasing (curve upward)
At time t=0 a moving cart on a horizontal track is at position 0.5 m. Using a motion detector, students generate a graph of the cart's velocity as a function of time, as shown above. At t=2.5s, the cart's position is most nearly: A. 0.5 m B. 1.25 m C. 1.75 m D. 2 m
C. 1.75 m
The motion of a particle along a straight line is represented by the position versus time graph above. At which of the labeled points on the graph is the magnitude of the acceleration of the particle greatest? A. A B. B C. C D. D E. E
C. C
(image shows: 4 stacks of boxes, each with 2 equal masses, besides the second stack showing 2M on M) The stacks of boxes shown in the figure above are inside an elevator that is moving upward. The masses of the boxes are given in terms of the mass M of the lightest box. Assume the elevator is moving at constant speed, and consider the bottom box in the stack that has two boxes of mass 2M. Let Ffloor be the force exerted by the floor on the box, Fg be the force exerted by gravity on the box, and Fbox be the force exerted by the top box on the bottom box. Which of the following best represents the forces exerted on the bottom box? A. Ffloor = Fgravity, pointing in opposite directions B. Ffloor=Fbox, pointing in opposite directions C. Ffloor pointing up; Fg and Fbox have 2 arrows pointing down, added would make it equal to Ffloor D. Fbox = Ffloor point up; Fg points down
C. Ffloor pointing up; Fg and Fbox have 2 arrows pointing down, added would make it equal to Ffloor
Three blocks are pushed along a rough surface by a force with magnitude P, as shown above. FC is the magnitude of the contact force between blocks 2 and 3, and Ff, FN, and FG are the magnitudes of the friction, normal, and gravitational forces on block 3, respectively. Which of the following is a correct free-body diagram for block 3? A. Fn=Fg (up and down); Fc and P pointing to the right, P>Fc; Ff facing left, shortest arrow B. Fn=Fg (up and down); P pointing right; Fc pointing left; P>Fc C. Fn=Fg (up and down); Fc pointing right; Ff pointing left; Fc> Ff D. Fn=Fg (up and down); Fc pointing to the right
C. Fn=Fg (up and down); Fc pointing right; Ff pointing left; Fc> Ff
The graphs above represent the position x, velocity v, and acceleration a as A. Rolling along the floor and then bouncing off a wall B. Rolling down one side of a bowl and then rolling up the other side C. Rolling up a ramp and then rolling back down D. Falling and then bouncing elastically off a hard floor
C. Rolling up a ramp and then rolling back down
Two blocks are connected by a rope, as shown above. The masses of the blocks are 5 kg for the upper block and 10 kg for the lower block. An upward applied force of magnitude F acts on the upper block. The system is moving and accelerating upward. A pair of scissors cuts the rope. Which of the following describes the motion of the 10 kg block immediately after the rope has been cut? A. The block continues to move upward and to accelerate upward. B. The block begins to move downward but continues to accelerate upward. C. The block continues to move upward but begins to accelerate downward. D. The block begins to move downward and to accelerate downward.
C. The block continues to move upward but begins to accelerate downward.
A space station has a mass M and orbits Earth in a circular orbit at a height above Earth's surface. An astronaut in the space station appears weightless because the astronaut seems to float. Which of the following claims is true about the force exerted on the astronaut by Earth? A. There is no force exerted on the astronaut by Earth because the astronaut is 400 km above the Earth's surface. B. The force exerted on the astronaut by Earth is less than the force exerted on Earth by the astronaut because the astronaut is 400 km above Earth's surface. C. The force exerted on the astronaut by Earth is equal to the force exerted on Earth by the astronaut. D. The force exerted on the astronaut by Earth is equal to the gravitational force of the space station that is exerted on the astronaut; the two equal forces balance to cause the astronaut to float.
C. The force exerted on the astronaut by Earth is equal to the force exerted on Earth by the astronaut.
A conveyor belt ramp of length 7m is inclined at 20° with respect to the horizontal and is used to move objects from one location to another location. When an object is placed on the conveyor belt, the object travels up the incline with a constant speed of 1.5 m/s . A motor is used to keep the conveyor belt moving. The mass of the objects that are placed on the conveyor belt are varied. For the system that only includes the object, which of the following claims best describes what happens to the mechanical energy of the system while the object is moving from the bottom of the ramp to the top of the ramp? A. The mechanical energy of the object increases because the gravitational potential energy increases as the object moves up the ramp. B. The mechanical energy of the object decreases because the force due to gravity from Earth does negative work on the object as it moves up the ramp. C. The mechanical energy of the object is constant because the kinetic energy of the object is constant. D. A determination of the change of the mechanical energy of the object cannot be made without knowing the power of the motor that is used to move the conveyor belt.
C. The mechanical energy of the object is constant because the kinetic energy of the object is constant.
An inclined track is secured to a table. The height of the highest point of the track above the tabletop is h1. The height from the tabletop to the floor is h2. A block of mass M is released from rest and slides down the track such that all frictional forces are considered to be negligible. The block leaves the track horizontally and strikes the ground at a distance D from the edge of the track as shown. Which of the following statements is correct about the scenario? Select two answers. A. If the block is released from a height 2h1, the block will land at a distance 2D away from the end of the track. B. If the block's mass is increased to 2M, the block will land at a distance 2D away from the edge of the track. C. The total mechanical energy of the system containing only the block increases from the moment of release to the moment it strikes the ground. D. The total mechanical energy of the block-Earth system remains constant.
C. The total mechanical energy of the system containing only the block increases from the moment of release to the moment it strikes the ground. D. The total mechanical energy of the block-Earth system remains constant.
The figure above shows the forces exerted on a block that is sliding on a horizontal surface: the gravitational force of 40 N, the 40 N normal force exerted by the surface, and a frictional force exerted to the left. The coefficient of friction between the block and the surface is 0.20. The acceleration of the block is most nearly A. 1.0 m/s^2 to the right B. 1.0 m/s^2 to the left C. 2.0 m/s^2 to the right D. 2.0 m/s^2 to the left
D. 2.0 m/s^2 to the left
A student wants to investigate the motion of a ball by conducting two different experiments, as shown in Figure 1 and Figure 2 above. In Experiment 1, the student releases a ball from rest and uses a slow-motion camera to film the ball as it falls to the ground. Using video analysis, the student is able to plot the ball's horizontal position x and vertical position y as a function of time t. In Experiment 2, the student horizontally rolls the same ball off a table, and uses video analysis to plot the ball's horizontal position x and vertical position y as a function of time t starting from the instant the ball leaves the table. The graphs from each experiment are shown above along with each graph's best-fit curve line. In experiment 1, what is the speed of the ball the instant it makes contact with the ground? A. 0 m/s B. 0.55 m/s C. 1.5 m/s D. 5.4 m/s
D. 5.4 m/s
A student wants to launch a toy dart toward a target that hangs from a light string. At time t=0, the dart is launched with an initial speed v0 at an angle θ0 above the horizontal ground. At the instant the dart is launched, the string is cut such that the target begins to fall straight down. The positive horizontal direction is considered to be to the right, and the positive vertical direction is considered to be up. Figure 1 shows a displacement-versus-time graph for the dart. Figure 2 shows a displacement-versus-time graph for the target. For both graphs, the component of the displacement is not indicated. Which displacement component, horizontal or vertical, is represented by the graph for each object? A. Dart: Horizontal, Target: Horizontal B. Dart: Vertical, Target: Horizontal C. Dart: Horizontal, Target: Vertical D. Dart: Vertical, Target: Vertical
D. Dart: Vertical, Target: Vertical
A student wants to launch a toy dart toward a target that hangs from a light string. At time t=0, the dart is launched with an initial speed v0 at an angle θ0 above the horizontal ground. At the instant the dart is launched, the string is cut such that the target begins to fall straight down. The positive horizontal direction is considered to be to the right, and the positive vertical direction is considered to be up. Which of the following graphs could represent the vertical component of the velocity as a function of time for the dart and the target immediately after the dart is launched and the target begins to fall? A. Dart and Target graphs are exactly the same; pointing downward from a point on the y-axis above the origin B. Dart and Target graphs are exactly the same; pointing downwards starting at the origin C. Dart: pointing downwards from the origin; Target: pointing downward from above the origin D. Dart: pointing downwards from above the origin; Target: pointing downwards starting at the origin
D. Dart: pointing downwards from above the origin; Target: pointing downwards starting at the origin
Object X and object Y are at rest on a horizontal surface. Object X is in contact with object Y. The force diagrams for both objects are shown above. Which two forces make up an action-reaction pair? A. F1 and F5, because both forces are exerted on different objects, have the same magnitude and are in opposite directions. B. F1 and F2, because both forces are exerted on the same object, have the same magnitude, and are in opposite directions. C. F2 and F5, because both forces are exerted on different objects, have the same magnitude, and are in the same direction. D. F3 and F6, because both forces are exerted on different objects, have the same magnitude, and are in opposite directions.
D. F3 and F6, because both forces are exerted on different objects, have the same magnitude, and are in opposite directions.
An astronaut stands on the surface of an asteroid. The astronaut then jumps such that the astronaut is no longer in contact with the surface. The astronaut falls back down to the surface after a short time interval. Which of the following forces CANNOT be neglected when analyzing the motion of the astronaut? A. The electromagnetic force between the subatomic particles of the astronaut and the subatomic particles of the asteroid. B. The strong nuclear force between the subatomic particles of the astronaut and the subatomic particles of the asteroid. C. The weak nuclear force between the subatomic particles of the astronaut and the subatomic particles of the asteroid. D. The gravitational force between the astronaut and the asteroid.
D. The gravitational force between the astronaut and the asteroid.
A cart is constrained to move along a straight line. A varying net force along the direction of motion is exerted on the cart. The cart's velocity v as a function of time t is shown in the graph above. The five labeled points divide the graph into four sections. Which of the following correctly ranks the magnitude of the average acceleration of the cart during the four sections of the graph? A. aCD>aAB>aBC>aDE B. aBC>aAB>aCD>aDE C. aAB>aBC>aDE>aCD D. aCD>aAB>aDE>aBC
D. aCD>aAB>aDE>aBC
