Physics

What is the tension in the angled string? (50 degree angle, mass on string=2kg) A. 19.6 N B. Not enough information C. 26 N D. 20.31 N E. 0 N

C. 26 N

A chicken is running in a circular path with a rotational speed of 1.52 rad/s. In what time interval does the chicken to complete one revolution? A. 118 s B. 4.13 s C. 4.77 s D. 8.26 s E. 2.07 s

B. 4.13 s

Tom is trying to move a crate across the floor. The crate's weight is 100N. The coefficient of kinetic friction is 0.3 and the coefficient of static friction is 0.5. How much force does Tom have to exert to start moving the crate initially at rest. A. 30 N B. 100 N C. 50 N D. 80 N

C. 50 N

A piano mover raises a 100 kg piano at a constant rate using a frictionless pulley system, as shown. With roughly what force is the mover pulling down on the rope? A. 1000 N B. 2000 N C. 500 N D. 250 N

C. 500 N

What is the maximum distance we can shoot a dart, provided our toy dart gun gives a maximum initial velocity of 7.76 m/s? A. More information needed. B. 12.28 m C. 6.14 m D. 3.88 m

C. 6.14 m

A 20.0 g ball is attached to a 120 cm-long string and moves in a horizontal circle. The string exerts a force on the ball that is equal to 0.200 N. What is the angle θ? A. 25◦ B. 37◦ C. 79◦ D. 41◦ E. 65◦

C. 79◦

The kinetic energy of a car is 8 ×10^6 J as it travels along a horizontal road. How much work is required to stop the car in 10 s? A. 8×10^7 J B. 8×10^5 J C. 8×10^6 J D. zero joules

C. 8×10^6 J

When an elevator accelerates upward, your weight reading on a scale is A. the normal weight B. zero C. greater D. less

C. greater

When you weigh yourself on a bathroom scale on a slight incline instead of a level surface, your weight reading on the scale will be A. more B. no different C. less

C. less

An object may have potential energy because of its A. momentum B. speed C. location D. acceleration

C. location

Swimmers at a water park have a choice of two frictionless water slides, as shown in the figure. Although both slides drop over the same height h, slide 1 is straight while slide 2 is curved, dropping quickly at first and then leveling out. How does the speed v1 of a swimmer reaching the bottom of slide 1 compare with v2, the speed of a swimmer reaching the end of slide 2? A. v1 >v2 B. v1 < v2 C. v1 = v2 D. The heavier swimmer will have a greater speed than the lighter swimmer, no matter which slide he uses. E. No simple relationship exists between v1 and v2.

C. v1 = v2

A stalled car is being pushed up a hill at constant velocity by three people. The net force on the car is A. down the hill and greater than the weight of the car. B. down the hill and equal to the weight of the car. C. zero D. up the hill and equal to the weight of the car. E. up the hill and greater than the weight of the car.

C. zero

A rock is tossed straight up with a speed of 20 m/s. When it returns, it falls into a hole 10 m deep. What is the rock's velocity as it hits the bottom of the hole? A. 0 m/s B. -10 m/s C. -12 m/s D. -24 m/s E. -20 m/s

D. -24 m/s

A rifle is aimed horizontally at a target 100 m away, and the bullet leaves the rifle barrel at 650 m/s. If the gun is aimed right at the bull's-eye, by how much does the bullet miss the center? A. 0.521 m B. 0.332 m C. Not enough information D. 0.116 m E. 0.712 m

D. 0.116 m

The following 4 masses are all moving with the same momentum. Which one is moving the fastest? A. 5 kg B. 10 kg C. 2 kg D. 1 kg

D. 1 kg

A car starts from rest at a stop sign. It accelerates at 2.0 m/s^2 for 6.0 seconds, coasts for 2.0 seconds, and then slows down at a rate of 1.5 m/s^2 for the next stop sign. How far apart are the stop signs? A. 72 m B. Not enough information C. 86 m D. 108 m E. 130 m

D. 108 m

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are v0x=140 m/s and v0y=84 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the x-component of the velocity of the shell at point P is closest to: A. 105 m/s B. 35 m/s C. zero D. 140 m/s E. 70 m/s

D. 140 m/s

It is possible to shoot an arrow at a speed of 90 m/s. Neglecting friction, how high would the arrow rise if shot straight up? A. 4.59 m B. 827 m C. 882 m D. 413 m

D. 413 m

Two 5000-kg rail cars roll without friction (one at 1 m/s, the other at 2 m/s) toward each other on a level track. They collide, couple, and roll together with a combined momentum of A. zero. B. 15,000 kg m/s. C. 10,000 kg m/s. D. 5000 kg m/s.

D. 5000 kg m/s.

An object moves with a velocity v. Suppose its velocity becomes 3v. The new kinetic energy will be ............. times the original kinetic energy. A. 1/3 B. 3 C. 1/9 D. 9 E. 1

D. 9

A ball is thrown straight up. At what point does the ball have the most energy? Ignore air resistance. A. At the highest point of its path. B. Just before it hits the ground. C. When the ball is halfway to the highest point of its path. D. Everywhere; the energy of the ball is the same at all of these points. E. When it is first thrown.

D. Everywhere; the energy of the ball is the same at all of these points.

A baseball is hit upward at an angle to the horizontal and travels along a parabolic arc before it strikes the ground. Which one of the following statements is necessarily TRUE? A. The velocity of the ball is a maximum when the ball is at the highest point in the arc. B. The velocity of the ball is zero m/s when the ball is at the highest point in the arc. C. The acceleration of the ball decreases as the ball moves upward. D. The x-component of the velocity of the ball is the same throughout the ball's flight.

D. The x-component of the velocity of the ball is the same throughout the ball's flight.

The block shown to the right is attached to a single rope. The tension in the rope is T = 30 N and the mass of the block is M = 2 kg. The block is: A. in equilibrium B. accelerating downward C. in free fall D. accelerating upward E. Not enough information

D. accelerating upward

When a ball falls downward, it may have a net force A. equal to its weight. B. of zero. C. equal to its weight minus air drag. D. any of the above E. none of the above

D. any of the above

Two boxes that are connected by a wire are pulled upward (P) with a constant speed. The tension in the wire is T. Which statement is correct: (top 25 N, bottom 100 N) A. T > P B. P = T + 100 N C. P + T = 125 N D. T = P E. P = T + 25 N

E. P = T + 25 N

A 3.0-kg cart moving to the right with a speed of 1.0 m/s has a head-on collision with a 5.0-kg cart that is initially moving to the left with a speed of 2.0 m/s. After the collision, the 3.0 kg cart is moving to the left with a speed of 1.0 m/s. What is the final velocity of the 5.0 kg cart? A. 0.8 m/s to the left B. 0.8 m/s to the right C. 2.0 m/s to the left D. zero m/s E. 2.0 m/s to the right

A. 0.8 m/s to the left

A car is traveling up a hill that is inclined at an angle of theta above the horizontal. Determine the ratio of the magnitude of the normal force to the weight of the car when θ= 15◦. A. 0.91 B. 0.65 C. 0.73 D. Not enough information

A. 0.91

What is m2 if both masses are moving with constant velocity. m1 = 2.0 kg; neglect friction. A. 1.2 kg B. 1.5 kg C. 2.0 kg D. Not enough information.

A. 1.2 kg

Two boxes, each of mass m = 4 kg, are being pulled along a horizontal frictionless surface. The tension in the rope connecting the boxes is 6 N. The acceleration of the lefthand box is: A. 1.5 m/s/s B. 3.0 m/s/s C. 0.33 m/s/s D. 0.67 m/s/s

A. 1.5 m/s/s

A 1.00-kg object is attached by a thread of negligible mass, which passes over a pulley of negligible mass, to a 2.00 kg object. The objects are positioned so that they are the same height from the floor and then released from rest. What are the speeds of the objects when they are separated vertically by 1.00 m? A. 1.81 m/s B. Not enough information C. 0 m/s D. 3 m/s

A. 1.81 m/s

Which requires more work, increasing a car's speed from 0 m/s to 10 m/s or from 10 m/s to 20 m/s? A. 10 m/s to 20 m/s B. It is the same in both cases. C. 0 m/s to 10 m/s

A. 10 m/s to 20 m/s

An object is moving with constant non-zero velocity in the +x direction. The position versus time graph of this object is A. a horizontal straight line. B. a straight line making an angle with the time axis. C. a parabolic curve. D. a vertical straight line.

B. a straight line making an angle with the time axis.

A 6.0 kg box is held at rest by two ropes that form 30◦ angles with the vertical. An external force F acts vertically downward on the box. The force exerted by each of the two ropes is denoted by T. A force diagram, showing the four forces that act on the box in equilibrium, is shown in the figure. The magnitude of force F is 410 N. The magnitude of force T is closest to: A. 271 N B. 235 N C. 188 N D. 376 N E. 470 N

A. 271 N

A tennis player smashes a ball of mass m horizontally at a vertical wall. The ball rebounds at the same speed v with which it struck the wall. Has the momentum of the ball changed, and if so, what is the magnitude of the change? A. 2mv B. 4mv C. mv D. 0 E. mv/2

A. 2mv

A book of mass 2.00 kg is pushed against the wall with a force of 30.0 N directed perpendicular to the wall. The magnitude of the normal force of the wall on the book is: A. 30.0 N B. 0 N C. 2.00 N D. 19.6 N

A. 30.0 N

An 8.0-g bullet is suddenly shot into a 4.0-kg block that is at rest on a frictionless horizontal surface, as shown in the figure. The bullet remains lodged in the block. The block then moves against a spring and compresses it by 3.7 cm. The spring constant of the spring is 2500 N/m. What was the initial speed v of the bullet? A. 460 m/s B. 500 m/s C. 440 m/s D. 520 m/s E. 480 m/s

A. 460 m/s

A projectile is fired at time t = 0.0 s, from point 0 at the edge of a cliff, with initial velocity components of v0x=30 m/s and v0y=100 m/s. The projectile rises, then falls into the sea at point P. The time of flight of the projectile is 25.0 s. In the figure, the magnitude of the velocity at time t = 15.0 is closest to: A. 56 m/s B. 249 m/s C. 49 m/s D. 37 m/s E. 237 m/s

A. 56 m/s

What is the tension in the rope? (60 kg man, pulley and 100 kg weight) A. 590 N B. Not enough information C. 392 N D. 100 N E. 980 N

A. 590 N

A 0.2 kg ball travels to the right at 30 m/s and is brought to a stop in a catcher's mitt. What is the magnitude of the impulse imparted to the ball? A. 6.0 kg.m/s B. 30 N C. 0 kg.m/s D. 6.0 m/s E. 6.0 J

A. 6.0 kg.m/s

There is a crash between a heavy truck and a small car. Choose the correct statement. A. During the collision, the force on the truck is equal to the force on the car. B. The car did not slow down during the collision, but the truck did. C. During the collision, the force on the truck is greater than the force on the car. D. The truck did not slow down during the collision, but the car did. E. During the collision, the force on the truck is smaller than the force on the car.

A. During the collision, the force on the truck is equal to the force on the car.

Susie is trying to lift a large heavy crate but she cannot move it at all. Which is true? Suppose F is applied force by Susie. A. F + N = W B. F + N > W C. F = N D. F + N < W

A. F + N = W

You are riding in an enclosed train car moving at 90 km/h. If you throw a baseball straight up, where will the baseball land? A. In your hand B. Behind you C. Not enough information D. In front of you

A. In your hand

Book A is raised from the floor to a point 2.0m above the floor. An identical book (B) is raised from a point 2.0m below the ceiling to the ceiling. Which book undergoes the greatest increase in gravitational potential energy? A. Same for both books B. Not enough information C. Book A D. Book B

A. Same for both books

When you throw a pebble straight up with initial speed V, it reaches a maximum height H with no air resistance. At what speed should you throw it up vertically so it will go twice as high? A. sqrt(2)V B. 8 V C. 4 V D. 2 V E. 16 V

A. sqrt(2)V

Compared with falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the A. stopping time is longer on the carpet. B. carpet provides a smaller impulse and a longer time. C. carpeted floor provides a smaller impulse. D. stopping time is shorter on the carpet.

A. stopping time is longer on the carpet.

When a car goes around a banked circular curve at the proper speed speed for the banking angle, what force cause it to follow the circular path? A. the normal force from the road B. gravity C. the friction force from the road D. No force causes the car to do this because the car is traveling at constant speed and therefore has no acceleration.

A. the normal force from the road

You carry a 7.0 kg bag of groceries 1.2 m above the ground at constant velocity across a 2.7 m room. How much work do you do on the bag in the process? A. 82 J B. 0.0 J C. 157 J D. 185 J

B. 0.0 J

At a stoplight, a moving car with mass 1700 kg runs into the back of a stationary truck with total mass 3900 kg. If the car exerts a force of 11,000 N on the truck during the collision, approximately what force does the truck exert on the car at the same time? A. 38,000 N B. 11,000 N C. 25,000 N D. 4800 N E. 17,000 N

B. 11,000 N

An astronaut takes a hammer which has a mass of 18 kg on Earth to the moon where the acceleration due to gravity is one-sixth the acceleration due to gravity on the Earth. What is the mass of the hammer on the moon? A. 0 kg B. 18 kg C. 180 kg D. 15 kg E. 3 kg F. 6 kg

B. 18 kg

You are standing on one side of a canyon looking across at a cliff on the other side that is 450 m away from you. Presume that the speed of sound in the air is 340 m/s. If you clap your hands, how much time does it take before the echo of your clap returns to you? A. 1.17 s B. 2.65 s C. 0.59 s D. 3.41 s E. 1.71 s

B. 2.65 s

At the highest point of the loop, calculate the minimum speed the block must have in order to stay in the loop. Neglect friction. m=3.0kg; h=2.2m; r=1m. A. 5.12 m/s B. 3.13 m/s C. 2.43 m/s D. Not enough information

B. 3.13 m/s

Mike is cutting the grass using a human-powered lawn mower. He pushes the mower with a force of 45 N directed at an angle of 41◦ below the horizontal direction. Calculate the work that Mike does on the mower each time he pushes it 9.1 m across the yard. A. 410 J B. 310 J C. 510 J D. 360 J

B. 310 J

Three railroad cars of equal mass, m=1000 kg, are on a track. Car A is approaching at a speed of v=4.0 m/s. Cars B and C are initially at rest. Car A collides and sticks to Car B, and then the pair of cars collides with Car C. Car C does not stick to the other two and heads off at a speed of vC=3.0 m/s to the right. What is the total momentum of the system of three cars before the collisions? A. 4 kg·m/s B. 4000 kg·m/s C. 1000 kg·m/s D. 7000 kg·m/s E. 1 kg·m/s

B. 4000 kg·m/s

A 4000 kg truck is parked on a 7.0◦ slope. Calculate the frictional force on the truck. A. 39000 N B. 4800 N C. Not enough information D. 40000 N E. 3000 N

B. 4800 N

A roadway is designed for traffic moving at a speed of 66 m/s. A curved section of the roadway is a circular arc of 290 m radius. The roadway is banked-so that a vehicle can go around the curve-with the lateral friction forces equal to zero. The angle at which the roadway is banked is closest to: A. 55◦ B. 57◦ C. 53◦ D. 51◦ E. 59◦

B. 57◦

The Chicago Sears Tower has height of about 443 m. If an object was dropped from the top of the tower, what would be the time it takes the object to reach the ground? A. Not enough information B. 9.40 s C. 8.68 s D. 0.01 s

B. 9.40 s

Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct? A. Both do positive work, but person X does twice the work of person Y. B. Both do zero work. C. Both do the same amount of positive work. D. Both do positive work, but person X does one-half the work of person Y. E. Both do positive work, but person X does four times the work of person Y.

B. Both do zero work.

A car travels at constant speed along a straight, level stretch of road. What can be said for certain about the net force acting on the car? A. It points along the direction of motion B. It is zero C. It points upward D. It points downward E. It points opposite the direction of motion

B. It is zero

Mary and Jim dive from an overhang into the lake below. Mary simply drops straight down from the edge. Jim takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below if there is no air resistance. A. Mary reaches the surface of the lake first. B. Mary and Jim will reach the surface of the lake at the same time. C. Cannot be determined without knowing the weight of both Mary and Jim. D. Cannot be determined without knowing the mass of both Mary and Jim. E. Jim reaches the surface of the lake first.

B. Mary and Jim will reach the surface of the lake at the same time.

A stone can slide down one of four different frictionless ramps, as shown in the figure. For which ramp will the speed of the ball be the greatest at the bottom? A. Ramp X B. The speed of the ball will be the same for all the ramps. C. Ramp Y D. Ramp Z E. Not enough information

B. The speed of the ball will be the same for all the ramps.

Three cars (car F, car G, and car H) are moving with the same speed and slam on their brakes. The most massive car is car F, and the least massive is car H. If the tires of all three cars have identical coefficients of kinetic friction with the road surface, which car travels the longest distance to skid to a stop? A. Car G B. They all travel the same distance in stopping. C. Car F D. Car H

B. They all travel the same distance in stopping.

The push P is directed at an angle θ below the horizontal, and the box remains a rest. The surface has some friction with the box. The normal force on the box due to the floor is equal to A. W + Pcosθ B. W + Psinθ C. W + P D. W - Psinθ E. W

B. W + Psinθ

How does a person standing on the ground explain why you, sitting on the left side of a slippery back car seat, slide to the right when the car makes a high-speed left turn? A. The car seat pushes you forward. B. You tend to move in a straight line and thus slide with respect to the seat that is moving to the left under you. C. There is a net outward force being exerted on you. D. The force of motion propels you forward.

B. You tend to move in a straight line and thus slide with respect to the seat that is moving to the left under you.

You want to load a box into the back of a truck. One way is to lift it straight upward at constant speed, as shown in the image above on the left. Alternatively, you can slide the box up a frictionless loading ramp at a constant speed, as shown in the image above on the right. Which of the following correctly compares the work that you would do on the box-Earth system in each case? A. You would do more work by pushing the box up the ramp, since the displacement of the system is greater. B. You would do the same amount of work in each case, since the energy change of the system is the same in both scenarios. C. You would do more work by pushing the box up the ramp, since the final kinetic energy of the system is greater. D. You would do more work by lifting the box straight upward, since the final gravitational potential energy of the system is greater. E. You would do the same amount of work in each case, since you would need to exert the same amount of force on each. F. You would do more work by lifting the box straight upward, since you must exert a greater force on the system.

B. You would do the same amount of work in each case, since the energy change of the system is the same in both scenarios.

A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will A. be in front of the package. B. be directly over the package. C. be behind the package. D. depend on the speed of the plane when the package was released.

B. be directly over the package.

A box is dragged a distance d across a floor by a force F which makes an angle θ with the horizontal. If the magnitude of the force is held constant but the angle θ is increased up to 90◦, the work done by the force in dragging the box A. first decreases, then increases. B. decreases. C. remains the same. D. first increases, then decreases. E. increases.

B. decreases.

Two boxes, each of mass m = 4 kg, are being pulled along a horizontal frictionless surface. The tension in the rope connecting the boxes is 6 N. The tension in the right hand rope is: A. equal to 6 N B. greater than 6 N C. less than 6 N

B. greater than 6 N

When a skier skies down a hill, the normal force exerted on the skier by the hill is A. greater than the weight of the skier B. less than the weight of the skier C. equal to the weight of the skier

B. less than the weight of the skier

You are making a circular turn in your car on a horizontal road when you hit a big patch of ice, causing the force of friction between the tires and the road to become zero. While the car is on the ice, it A. moves along a straight-line path toward the center of the circle. B. moves along a straight-line path in its original direction. C. continues to follow a circular path, but with a radius larger than the original radius. D. moves along a straight-line path away from the center of the circle. E. moves along a path that is neither straight nor circular.

B. moves along a straight-line path in its original direction.

A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory A. the ball's acceleration is zero but its velocity is not zero. B. neither the ball's velocity nor its acceleration are zero. C. the ball's acceleration points upward. D. the ball's velocity points downward. E. both the velocity and the acceleration of the soccer ball are zero.

B. neither the ball's velocity nor its acceleration are zero.

A person carries a 25.0-N rock through the path shown in the figure, starting at point A and ending at point B. The total time from A to B is 1.50 min. How much work did gravity do on the rock between A and B? A. 20.0 J B. 625 J C. 0 J D. 275 J E. 75 J

C. 0 J

A boy throws a rock with an initial velocity of 3.13 m/s at 30.0 degrees above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory? A. 0.282 s B. 0.441 s C. 0.160 s D. 0.313 s

C. 0.160 s

A ball rolls horizontally off a table and lands on the floor. The horizontal distance between the position at which the ball lands and the edge of the table is 0.50 m, and the tabletop is 0.80 m above the floor. What is the ball's speed when it leaves the table? A. 0 m/s B. 4.3 m/s C. 1.2 m/s D. 2.4 m/s E. Not enough information

C. 1.2 m/s

A block slides down a frictionless inclined ramp. If the ramp angle is 17.0◦ and the length of it is 20.0 m, find the speed of the block as it reaches the end of the ramp, assuming it started sliding from rest at the top. A. 19.6 m/s B. 114 m/s C. 10.7 m/s D. 7.57 m/s

C. 10.7 m/s

One end of a rope is pulled with 100 N, while the opposite end also is pulled with 100 N. The tension in the rope is A. 50 N B. 200 N C. 100 N D. 0 N

C. 100 N

Katie serves a ping pong ball by tossing the ball straight up and hitting the ball once it returns to the same point where it was tossed. If the ball is in the air for 0.45 s, what is the ball's initial speed after being tossed? Ignore air resistance. A. 1.7 m/s B. 1.1 m/s C. 2.2 m/s D. Not enough information E. 3.3 m/s

C. 2.2 m/s

Standing on the edge of a cliff, you throw a rock straight up. Your friend releases a rock over the edge of the cliff. Assume air resistance is negligible. While in the air, the acceleration of the two rocks are A. Different in terms of their directions (upward and downward) B. Different most of the time C. Always the same D. Same in direction but different in magnitude

C. Always the same

A football is kicked at an angle q with respect to the horizontal. Which one of the following statements best describes the acceleration of the football during this event if air resistance is neglected? A. The acceleration starts at 9.8 m/s^2 and drops to some constant lower value as the ball approaches the ground. B. The acceleration is positive as the football rises, and it is negative as the football falls. C. The acceleration is 9.8 m/s^2 at all times. D. The acceleration is zero m/s^2 at all times. E. The acceleration is zero m/s^2 when the football has reached the highest point in its trajectory.

C. The acceleration is 9.8 m/s^2 at all times.

You throw a baseball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down. A. The work is negative on the way up and on the way down because gravity is always downward. B. The work is positive on the way up and positive on the way down. C. The work is negative on the way up and positive on the way down. D. The work is positive on the way up and negative on the way down.

C. The work is negative on the way up and positive on the way down.

In two-dimensional motion in the x-y plane, what is the relationship between the x part of the motion to the y part of the motion? A. The x part of the motion is linearly dependent on the y part of the motion. B. The x part of the motion goes as the square of the y part of the motion. C. The x part of the motion is independent of the y part of the motion. D. If the y part of the motion is in the vertical direction, then x part of the motion is dependent on the y part. E. The y part of the motion goes as the square of the x part of the motion.

C. The x part of the motion is independent of the y part of the motion.

You are standing in a moving bus, facing forward, when you suddenly slide forward as the bus comes to an immediate stop. What force caused you to slide forward? A. the force due to friction between you and the floor of the bus B. gravity C. There is not a force causing you to slide forward. D. the normal force due to your contact with the floor of the bus

C. There is not a force causing you to slide forward.

An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is A. a vertical straight line. B. a straight line making an angle with the time axis. C. a horizontal straight line. D. a parabolic curve.

C. a horizontal straight line.

When Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard, the speed of the skateboard A. neither decreases nor increases. B. increases. C. decreases.

C. decreases.

A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is A. twice as much. B. one-fourth as much. C. one-half as much. D. four times as much. E. the same.

D. four times as much.

When an object moves in uniform circular motion, the direction of its acceleration is A. in the opposite direction of its velocity vector. B. depends on the speed of the object. C. in the same direction as its velocity vector. D. is directed toward the center of its circular path. E. is directed away from the center of its circular path.

D. is directed toward the center of its circular path.

If a monkey floating in outer space throws his hat away, the hat and the monkey will both A. move away from each other at the same speed. B. move a short distance and then slow down. C. come to a stop after a few minutes. D. move away from each other, but at different speeds. E. move a short distance and then go faster.

D. move away from each other, but at different speeds.

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are v0x=490 m/s and v0y=35 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the y-component of the velocity of the shell of point P is closest to: A. -40 m/s B. -70 m/s C. +40 m/s D. zero E. +70 m/s

D. zero

A man on his luge (total mass of 88.0 kg) emerges onto the horizontal straight track at the bottom of the hill with a speed of 28.0 m/s. If the luge and rider slow at a constant rate of 28.0 m/s^2, what is the total work done on them by the force that slows them to a stop? A. +1.25 × 10^2 J B. -1.25 × 10^2 J C. +3.45 × 10^4 J D. 0 J E. -3.45 × 10^4 J

E. -3.45 × 10^4 J

Three railroad cars of equal mass, m=1000 kg, are on a track. Car A is approaching at a speed of v=4.0 m/s. Cars B and C are initially at rest. Car A collides and sticks to Car B, and then the pair of cars collides with Car C. Car C does not stick to the other two and heads off at a speed of vC=3.0 m/s to the right. What is the final speed of Cars A and B, vAB, after having collided with Car C? A. 3 m/s B. 1 m/s C. 1.5 m/s D. 2 m/s E. 0.5 m/s

E. 0.5 m/s

Mountain goats can easily scale slopes angled at 60◦ from horizontal. What is the normal force acting on a mountain goat that weighs 900 N and is standing on such a slope? A. 750 N B. 240 N C. 610 N D. 300 N E. 450 N

E. 450 N

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are v0x=940 m/s and v0y=96 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the y-coordinate of point P is closest to: A. 45,080 m B. 940 m C. 45,550 m D. 90,160 m E. 470 m

E. 470 m

In the figure below, a 4.0 kg ball is on the end of a 1.6m rope which is fixed at 0. The ball is held at A, with the rope horizontal, and is given an initial downward velocity. The ball moves through three quarters of a circle and arrives at B, with the rope barely under tension. The initial velocity of the ball, at A, is closest to: A. 7.9 m/s B. 4.0 m/s C. 6.3 m/s D. 5.6 m/s E. 6.9 m/s

E. 6.9 m/s

A 550 kg elevator accelerates upward at 1.2 m/s^2 for the first 15 m of its motion. How much work is done during this part of its motion by the cable that lifts the elevator? A. 62 kJ B. 70 kJ C. 0 J D. Not enough information E. 91 kJ

E. 91 kJ

Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct? A. Both do positive work on the wall, but person X does twice the work of person Y. B. Both do the same amount of positive work on the wall. C. Both do positive work on the wall, but person X does four times the work of person Y. D. Both do positive work on the wall, but person X does one-half the work of person Y. E. Both do zero work on the wall.

E. Both do zero work on the wall.

A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rock's motion are true just before it hits the ground? A. Its velocity is vertical. B. Its horizontal velocity component is zero. C. Its vertical velocity component is the same as it was just as it was launched. D. Its speed is the same as it was just as it was launched. E. Its horizontal velocity component is the same as it was just as it was launched.

E. Its horizontal velocity component is the same as it was just as it was launched.

You push on box G that is next to box H, causing both boxes to slide along the floor, as shown in the figure. The reaction force to your push is A. the upward force of the floor n box G. B. the push of box H on box G. C. the push of box G on box H. D. the acceleration of box G. E. the push of box G against you.

E. the push of box G against you.

A small container holds a volume of 350 cm^3 of fluid. What is this volume in m^3? A. 3.50×10^4 m^3 B. 3.50 m^3 C. 3.50×10^2 m^3 D. 3.50×10^-2 m^3 E. 3.50×10^6 m^3 F. 3.50×10^-4 m^3 G. 3.50×10^8 m^3

F. 3.50×10^-4 m^3

The crate shown to the right has a weight of 200 N and is being pulled by a rope with a force of 450 N at an angle θ=35◦ as shown. A person with a weight of 650 N is sitting on the crate. What is the normal force of the floor on the crate under these conditions? A. 650 N B. 1110 N C. 200 N D. 481 N E. 850 N F. 592 N

F. 592 N

You can launch a projectile with a fixed initial speed but at any angle above the horizontal, and it feels no air resistance. The time for it to return to the ground does not depend on the angle at which you launch it. True False

False

If a stone is dropped with an initial gravitational potential energy of 100 J but reaches the ground with a kinetic energy of only 75 J, this is a violation of the principle of conservation of energy. true or false

false