physics 1111 final exam

A driver in a 1000 kg car traveling at 24 m/s slams on the brakes and skids to a stop. If the coefficient of friction between the tires and the road is 0.80, how long will the skid marks be? Select one: A.46 m B.34 m C.37 m D.30 m

37 m

A 15 kg block is on a ramp that is inclined at 20° above the horizontal. It is connected by a string to a 19 kg mass that hangs over the top edge of the ramp. Assuming that frictional forces may be neglected, what is the magnitude of the acceleration of the 19 kg block? (See the figure.) Select one: A.4.5 m/s2 B.3.8 m/s2 C.4.0 m/s2 D.4.2 m/s2

4.0 m/s2

A ball is thrown downward in the absence of air resistance. After it has been released, which statement(s) concerning its acceleration is correct? (There could be more than one correct choice.) Select one: A.Its acceleration is constantly increasing. B.Its acceleration is zero. C.Its acceleration is greater than g. D.Its acceleration is constant. E.Its acceleration is constantly decreasing.

Its acceleration is constant

Which of the following situations is impossible? Select one: A.An object has velocity directed east and acceleration directed west. B.An object has constant non-zero acceleration and changing velocity. C.An object has constant non-zero velocity and changing acceleration. D.An object has zero velocity but non-zero acceleration. E.An object has velocity directed east and acceleration directed east.

An object has constant non-zero velocity and changing acceleration

Which of the following quantities has units of a velocity? (There could be more than one correct choice.) Select one or more: A.9.8 m/s downward B.186,000 mi C.40 km southwest D.-120 m/s E.9.8 m/s2 downward

9.8 m/s downward; -120 m/s

A person with a mass 78 kg of is riding in an elevator that is accelerating upward at 1.8 m/s/ s. What is the person's apparent weight? (Use g = 9.8 m/s2.) Select one: A.620 N B.960 N C.900 N D.760 N

900 n

A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff if air resistance is negligibly small? Select one: A.77 m B.91 m C.43 m D.22 m

91 m

A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s. The vector sum of all the forces acting on this crate must point down the ramp. Select one: True False

false

If a 5.0 kg box is pulled simultaneously by a 10.0 N force and a 5.0 N force, then its acceleration must be 3.0 m/s2. Select one: True False

false

If the acceleration of an object is zero, then that object cannot be moving. Select one: A. True B. False

false

If the rockets of a spaceship in outer space (far from all gravity) suddenly lose power and go off, the spaceship will gradually slow to a stop. Select one: True False

false

If the velocity of an object is zero at some point, then its acceleration must also be zero at that point. Select one: A.True B.False

false

If the velocity of an object is zero, then that object cannot be accelerating. Select one: A. True B. False

false

In a collision between a huge SUV and a small compact car, the SUV exerts a larger force on the compact than the compact exerts on the SUV. Select one: True False

false

You throw a stone vertically upward, and it feels no air resistance. Once it is free of your hand but moving upward, the two forces acting on it are the downward pull of gravity and the upward force due to its motion. Select one: True False

false

A 10-kg rock and a 20-kg rock are thrown upward with the same initial speed v0 and experience no significant air resistance. If the 10-kg rock reaches a maximum height h, what maximum height will the 20-kg ball reach? Select one: A.4h B.h/4 C.2h D.h E.h/2

h

Two objects are dropped from a bridge, an interval of 1.0 s apart. Air resistance is negligible. During the time that both objects continue to fall, their separation Select one: A.increases at first, but then stays constant. B.stays constant. C.decreases at first, but then stays constant. D.increases. E.decreases.

increases

An object is moving to the right, and experiencing a net force that is directed to the right. The magnitude of the force is decreasing with time. The speed of the object is Select one: A.decreasing. B.constant in time. C.increasing.

increasing

For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration Select one: A.continuously decreases. B.is always zero. C.first decreases and then increases. D.remains a non-zero constant. E.continuously increases.

is always zero

When a ball is thrown straight up with no air resistance, the acceleration at its highest point Select one: A.reverses from upward to downward B.is upward C.is zero D.reverses from downward to upward E.is downward

is downward

An object moving in the +x direction experiences an acceleration of +2.0 m/s2. This means the object Select one: A.is decreasing its velocity by 2.0 m/s every second. B.travels 2.0 m in every second. C.is traveling at 2.0 m/s. D.is increasing its velocity by 2.0 m/s every second.

is increasing its velocity by 2.0 m/s every second

You drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. Your average speed over the 12 km drive will be Select one: A.exactly 38 km/h. B.greater than 70 km/h. C.equal to 70 km/h. D.less than 70 km/h. E.It cannot be determined from the information given because we must also know directions traveled.

less than 70 km/h

A person who normally weighs 700 N is riding in an elevator that is moving upward but slowing down at a steady rate. If this person is standing on a bathroom scale inside the elevator, what would the scale read? Select one: A.more than 700 N B.700 N C.less than 700 N D.It could be more or less than 700 N, depending on whether the magnitude of the acceleration is greater than or less than 9.8 m/s2.

less than 700 n

If the velocity versus time graph of an object is a straight line making an angle of +30° (counter clockwise) with the time axis, the object is Select one: A.moving with constant non-zero speed. B.moving with constant non-zero acceleration. C.at rest. D.moving with increasing acceleration.

moving with constant non-zero acceleration

If the velocity versus time graph of an object is a horizontal line, the object is Select one: A.moving with zero acceleration. B.moving with constant non-zero acceleration. C.at rest. D.moving with increasing speed.

moving with zero acceleration

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

neither the ball's velocity nor its acceleration are zero

A ball is thrown vertically upward, reaches a highest point, and comes back down. At the top of its path, what forces, if any, act on the ball? Explain your answer. Select one: A.no forces B.only a downward force C.only an upward force D.an upward and a downward force, opposing and equal

only a downward force

For general projectile motion with no air resistance, the horizontal component of a projectile's velocity Select one: A.remains zero. B.remains a non-zero constant. C.continuously increases. D.first decreases and then increases. E.continuously decreases.

remains a non-zero constant

For general projectile motion with no air resistance, the vertical component of a projectile's acceleration Select one: A.remains a non-zero constant. B.continuously increases. C.first decreases and then increases. D.is always zero. E.continuously decreases.

remains a non-zero constant

Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. Neglect air resistance. As time progresses, the difference in their speeds Select one: A.remains constant. B.increases. C.decreases. D.cannot be determined from the information given.

remains constant

A 10-kg rock and 20-kg rock are dropped from the same height and experience no significant air resistance. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground? Select one: A.4T B.2T C.T/4 D.T E.T/2

t

A ball is thrown horizontally from the top of a tower at the same instant that a stone is dropped vertically. Which object is traveling faster when it hits the level ground below if neither of them experiences any air resistance? Select one: A.It is impossible to tell because we do not know their masses. B.the stone C.the ball D.Both are traveling at the same speed.

the ball

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 Select one: A.the push of box H on box G. B.the acceleration of box G. C.the push of box G on box H. D.the upward force of the floor n box G. E.the push of box G against you.

the push of box G against you

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. If there is no air resistance, when they reach the lake below Select one: A.the splashdown speed of John is larger than that of James. B.they will both have the same splashdown speed. C.the splashdown speed of John must be 25 m/s larger than that of James. D.the splashdown speed of James is larger than that of John. E.the splashdown speed of James must be 9.8 m/s larger than that of John.

the splashdown speed of John is larger than that of James

A large truck collides head-on with a cyclist. During the collision Select one: A.the truck exerts a force on the cyclist, but the cyclist exerts no force on the truck. B.the truck exerts a smaller amount of force on the cyclist than the cyclist exerts on the truck. C.the truck exerts the same amount of force on the cyclist as the cyclist exerts on the truck. D.the truck exerts a greater amount of force on the cyclist than the cyclist exerts on the truck.

the truck exerts the same amount of force on the cyclist as the cyclist exerts on the truck

From the edge of a roof top you toss a green ball upwards with initial speed v0 and a blue ball downwards with the same initial speed. Air resistance is negligible. When they reach the ground below Select one: A.the blue ball will be moving faster than the green ball. B.the two balls will have the same speed. C.the green ball will be moving faster than the blue ball.

the two balls will have the same speed

A ball is tossed vertically upward. When it reaches its highest point (before falling back downward), Select one: A.the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is zero. B.the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward. C.the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is directed downward. D.None of the above

the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward

A satellite is in orbit around the earth. The satellite pulls just as hard on the earth as the earth pulls on the satellite. Select one: True False

true

An elevator suspended by a vertical cable is moving downward but slowing down. The tension in the cable must be greater than the weight of the elevator. Select one: True False

true

Consider a car that travels between points A and B. The car's average speed can be greater than the magnitude of its average velocity, but the magnitude of its average velocity can never be greater than its average speed. Select one: A.True B.False

true

Consider a deer that runs from point A to point B. The distance the deer runs can be greater than the magnitude of its displacement, but the magnitude of the displacement can never be greater than the distance it runs. Select one: A. true B. false

true

The slope of a position versus time graph gives Select one: A.velocity. B.displacement. C.acceleration. D.the distance traveled.

velocity

A boy throws a rock with an initial velocity of at 30.0° above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory if air resistance is negligibly small and g = 9.80 m/s2? Select one: A.0.313 s B.0.441 s C.0.160 s D.0.282 s

0.160 s

A 80 N force is needed to slide 50 kg a box across a flat surface at a constant velocity. What is the coefficient of kinetic friction between the box and the floor? (Use g = 9.8 m/s2.) Select one: A.0.15 B.0.13 C.0.18 D.0.16

0.18

An object at rest on an inclined plane starts to slide when the incline angle is increased to 17°. What is the coefficient of static friction between the object and the incline? (Use g = 9.8 m/s2.) Select one: A.0.37 B.0.31 C.0.33 D.0.27

0.37

A ball is thrown with an initial velocity of 20 m/s at an angle of 60° above the horizontal. If we can neglect air resistance, what is the horizontal component of its instantaneous velocity at the exact top of its trajectory? Select one: A.17 m/s B.10 m/s C.20 m/s D.zero

10 m/s

A plane flying horizontally at a speed of 50 m/s and at an elevation of 160 m drops a package, and 2.0 s later it drops a second package. How far apart will the two packages land on the ground if air resistance is negligible? Select one: A.160 m B.320 m C.100 m D.180 m

100 m

Which of the following quantities has units of a displacement? (There could be more than one correct choice.) Select one or more: A.186,000 mi B.40 km southwest C.-120 m/s D.32 ft/s2 vertically downward E.9.8 m/s2

186,000 mi; 40 km southwest

Joe and Bill are playing tug-of-war. Joe is pulling with a force of 200 N. Bill is simply hanging on to the rope. Neither person is moving. What is the tension of the rope? Select one: A.300 N B.0 N C.200 N D.400 N

200 n

A hockey puck slides off the edge of a platform with an initial velocity of 20 m/s horizontally. The height of the platform above the ground is 2.0 m. What is the magnitude of the velocity of the puck just before it touches the ground? You can neglect air resistance. Select one: A.6.3 m/s B.21 m/s C.22 m/s D.24 m/s E.25 m/s

21 m/s

A football kicker is attempting a field goal from 44m out. The ball is kicked and just clears the lower bar with a time of flight of 2.9 s If the angle of the kick was 45°, what was the initial speed of the ball, assuming no air resistance? Select one: A.19.7 m/s B.39 m/s C.2.2 m/s D.21.5 m/s

21.5 m/s

A child on a sled starts from rest at the top of a 15.0° slope. If the trip to the bottom takes how long is the slope? Assume that frictional forces may be neglected. Select one: A.147 m B.586 m C.293 m D.1130 m

293 m

A Ferrari accelerates from 0 to 100.0 km/h in 4.80 s. What force (in Newtons) does a passenger of mass 68.0 kg experience during acceleration? Select one: A.311 N B.342 N C.82.0 N D.394 N

394 n

A child pulls on a wagon handle at an angle 37° above the horizontal with a force of 45 N. If the wagon accelerates at 8.1 m/s2 horizontally, what is the mass of the wagon? Assume frictional forces are negligible. Select one: A.4.4 kg B.3.1 kg C.3.7 kg D.5.6 kg

4.4 kg

A 6.0 kg box slides down an inclined plane that makes an angle of 39° with the horizontal. If the coefficient of kinetic friction is 0.19, at what rate does the box accelerate down the slope? (Use g = 9.8 m/s2.) Select one: A.5.2 m/s2 B.5.5 m/s2 C.6.2 m/s2 D.4.7 m/s2

4.7 m/s2

A person is using a rope to lower a 5.0-N bucket into a well with a constant speed of 2.0 m/s. What is the magnitude of the force exerted by the rope on the bucket? Select one: A.0.00 N B.10 N C.2.0 N D.49 N E.5.0 N

5.0 n

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

500 n

A truck is using a hook to tow a car whose mass is one quarter that of the truck. If the force exerted by the truck on the car is 6000 N, then the force exerted by the car on the truck is Select one: A.12000 N. B.6000 N. C.1500 N. D.24000 N. E.We need to know if the car is accelerating to answer this question.

6000 n

A fish is to be weighed at the harbor. If the mass of the fish is 69.0 kg, what will be the reading on the scale? (Use g = 9.8 m/s2.) Select one: A.744 N B.7.74 N C.7.04 N D.676 N

676 n

A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18 m. With what speed was it thrown, assuming negligible air resistance? Select one: A.7.4 m/s B.8.1 m/s C.6.1 m/s D.8.9 m/s

8.1 m/s

A tightrope walker walks across 30 m long wire tied between two poles. The center of the wire is displaced vertically downward by 1m when he is halfway across. If the tension in both halves of the wire at this point is 6294 N what is the mass of the tightrope walker? Neglect the mass of the wire. Select one: A.85 kg B.74 kg C.91 kg D.43 kg

85 kg

A racing car accelerates uniformly from rest along a straight track. This track has markers spaced at equal distances along it from the start, as shown in the figure. The car reaches a speed of 140 km/h as it passes marker 2.Where on the track was the car when it was traveling at half this speed, that is at 70 km/h? Select one: A.Between marker 1 and marker 2 B.Before marker 1 C.At marker 1

Between marker 1 and marker 2

Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30° above the horizontal. Which of the following statements are true about just as the snowballs reach the ground below? (There could be more than one correct choice.) Select one or more: A.Both snowballs hit the ground at the same time. B.Both snowballs will hit the ground with the same speed. C.Mary's snowball reaches the ground before Debra's snowball. D.Mary's snowball will have a higher speed than Debra's snowball. E.Debra's snowball will have a higher speed than Mary's snowball.

Both snowballs will hit the ground with the same speed.; Mary's snowball reaches the ground before Debra's snowball.

Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30° above the horizontal. Which of the following statements are true about just before the snowballs reach the ground below? (There could be more than one correct choice.) Select one or more: A.Both snowballs will take the same amount of time to hit the ground. B.Debra's snowball will stay in the air longer than Mary's snowball. C.Mary's snowball has a greater downward acceleration than Debra's snowball. D.Debra's snowball has exactly the same acceleration as Mary's snowball. E.Mary's snowball will stay in the air longer than Debra's snowball.

Debra's snowball will stay in the air longer than Mary's snowball; Debra's snowball has exactly the same acceleration as Mary's snowball

A 20-ton truck collides with a 1500-lb car. Which of the following statements must be true? Select one: A.The car did not slow down during the collision, but the truck did. B.During the collision, the force on the truck is equal to the force on the car. C.During the collision, the force on the truck is smaller than the force on the car. D.During the collision, the force on the truck is greater then the force on the car. E.The truck did not slow down during the collision, but the car did.

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

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? (There could be more than one correct choice.) Select one: A.Its horizontal velocity component is zero. B.Its speed is the same as it was just as it was launched. C.Its velocity is vertical. D.Its horizontal velocity component is the same as it was just as it was launched. E.Its vertical velocity component is the same as it was just as it was launched.

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

A ball is thrown straight up, reaches a maximum height, then falls to its initial height. Which of the following statements about the direction of the velocity and acceleration of the ball as it is going up is correct? Select one: A.Both its velocity and its acceleration point upward. B.Both its velocity and its acceleration points downward. C.Its velocity points downward and its acceleration points upward. D.Its velocity points upward and its acceleration points downward.

Its velocity points upward and its acceleration points downward

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John 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. Select one: A.John reaches the surface of the lake first. B.Cannot be determined without knowing the weight of both James and John. C.James reaches the surface of the lake first. D.James and John will reach the surface of the lake at the same time. E.Cannot be determined without knowing the mass of both James and John.

James and John will reach the surface of the lake at the same time

A person gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. The cart travels forward along the floor, gradually slowing as it moves. Consider the horizontal force(s) on the cart while it is moving forward and slowing. Which of the following statements is correct? Select one: A.Only a forward force is acting, which diminishes with time. B.Only a backward force is acting, no forward force. C.Both a forward and a backward force are acting on the cart, but the backward force is larger. D.Both a forward and a backward force are acting on the cart, but the forward force is larger.

Only a backward force is acting, no forward force

A woman is straining to lift a large crate, without success. It is too heavy. We denote the forces on the crate as follows: P is the upward force being exerted on the crate by the person, C is the contact force on the crate by the floor, and W is the weight of the crate. How are the magnitudes of these forces related, while the person is trying unsuccessfully to lift the crate? Select one: A.P + C = W B.P + C > W C.P = C D.P + C < W

P+C=W

Bill and Susan are both standing on identical skateboards (with really good ball bearings), initially at rest. Bill weighs three times as much as Susan. Bill pushes horizontally on Susan's back, causing Susan to start moving away from Bill. Immediately after Bill stops pushing, Select one: A.Susan is moving away from Bill, and Bill is stationary. B.Susan and Bill are moving away from each other, and Susan's speed is three times less than that of Bill. C.Susan and Bill are moving away from each other, and Susan's speed is three times that of Bill. D.Susan and Bill are moving away from each other, with equal speeds.

Susan and Bill are moving away from each other, and Susan's speed is three times that of Bill

Under what condition is average velocity equal to the average of the object's initial and final velocity? Select one: A.This can occur only when the velocity is zero. B.This can only occur if there is no acceleration. C.The acceleration is constant. D.The acceleration must be constantly increasing. E.The acceleration must be constantly decreasing.

The acceleration is constant

A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct? Select one: A.The acceleration is downward at all points in the motion. B.The acceleration is downward at all points in the motion except that is zero at the highest point. C.On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero. D.On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero. E.Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration.

The acceleration is downward at all points in the motion

Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct? Select one: A.The acceleration is equal to zero. B.The acceleration is constantly increasing. C.The acceleration is a constant non-zero value. D.The acceleration is constantly decreasing.

The acceleration is equal to zero

The motions of a car and a truck along a straight road are represented by the velocity-time graphs in the figure. The two vehicles are initially alongside each other at time t = 0.At time T, what is true of the distances traveled by the vehicles since time t = 0? Select one: A.The truck will have travelled further than the car. B.The truck will not have moved. C.The car will have travelled further than the truck. D.They will have traveled the same distance.

The car will have travelled further than the truck

Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object. Select one: A.The displacement is either greater than or equal to the distance traveled. B.The displacement can be either greater than, smaller than, or equal to the distance traveled. C.The displacement is always equal to the distance traveled. D.The displacement is either less than or equal to the distance traveled.

The displacement is either less than or equal to the distance traveled

When a 45-kg person steps on a scale in an elevator, the scale reads a steady 480 N. Which of the following statements must be true? (There could be more than one correct choice.) Select one or more: A.The elevator is accelerating upward at a constant rate. B.The elevator is moving upward at a constant rate. C.The elevator is accelerating downward at a constant rate. D.The elevator is moving downward at a constant rate. E.From the given information, we cannot tell if the elevator is moving up or down.

The elevator is accelerating downward at a constant rate; From the given information, we cannot tell if the elevator is moving up or down

Which of the following statements are true about an object in two-dimensional projectile motion with no air resistance? (There could be more than one correct choice.) Select one: A.The speed of the object is constant but its velocity is not constant. B.The speed of the object is zero at its highest point. C.The horizontal acceleration is always zero and the vertical acceleration is always a non-zero constant downward. D.The acceleration of the object is +g when the object is rising and -g when it is falling. E.The acceleration of the object is zero at its highest point.

The horizontal acceleration is always zero and the vertical acceleration is always a non-zero constant downward

An object is moving with a constant velocity. Which statement(s) MUST be true? Select one: A.The net force on the object is zero. B.A small net force is acting on the object, in the direction of motion. C.No forces are acting on the object. D.Two of the above statements are true.

The net force on the object is zero

An object is moving with constant non-zero velocity. Which of the following statements about it must be true? Select one: A.A constant force is being applied to it in the direction of motion. B.Its acceleration is in the same direction as it velocity. C.A constant force is being applied to it perpendicular to the direction of motion. D.The net force on the object is zero. E.A constant force is being applied to it in the direction opposite of motion.

The net force on the object is zero

An object of mass m rests on a flat table. The earth pulls on this object with a force of magnitude mg. What is the reaction force to this pull? Select one: A.The table pushing down on the floor with force mg. B.The object pushing down on the table with force mg. C.The table pulling upward on the Earth with force mg. D.The object pulling upward on the Earth with force mg. E.The table pushing up on the object with force mg.

The object pulling upward on the Earth with force mg

Brick A is dropped from the top of a building. Brick B is thrown straight down from the same building, and neither one experiences appreciable air resistance. Which statement about their accelerations is correct? Select one: A.The acceleration of A is greater than the acceleration of B. B.The two bricks have exactly the same acceleration. C.Neither brick has any acceleration once it is released. D.The acceleration of B is greater than the acceleration of A.

The two bricks have exactly the same acceleration

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? Select one: A.the normal force due to your contact with the floor of the bus B.gravity C.the force due to friction between you and the floor of the bus D.There is not a force causing you to slide forward.

There is not a force causing you to slide forward

Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? Neglect air resistance. Select one: A.They are traveling at the same speed. B.The one thrown down is traveling faster. C.The one thrown up is traveling faster. D.It is impossible to tell because the height of the building is not given.

They are traveling at the same speed

In an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the two pebbles. Select one: A.The thrown pebble hits first. B.They hit at the same time. C.The dropped pebble hits first. D.We cannot tell without knowing which pebble is heavier.

They hit at the same time

A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a, what is the acceleration of the 20-kg rock? Select one: A.2a B.a/2 C.4a D.a E.a/4

a

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

a horizontal straight line

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

a parabolic curve

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

a straight line making an angle with the time axis

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

a straight line making an angle with the time axis

The slope of a velocity versus time graph gives Select one: A.the distance traveled. B.displacement. C.acceleration. D.velocity.

acceleration

If the position versus time graph of an object is a horizontal line, the object is Select one: A.moving with constant non-zero speed. B.moving with constant non-zero acceleration. C.at rest. D.moving with increasing speed.

at rest

An auto manufacturer advertises that their car can go "from zero to sixty in eight seconds." This is a description of what characteristic of the car's motion? Select one: A.instantaneous speed B.average acceleration C.average speed D.displacement E.instantaneous acceleration

average acceleration

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 Select one: A.be behind the package. B.depend on the speed of the plane when the package was released. C.be in front of the package. D.be directly over the package.

be directly over the package

A horse pulls a cart with force . As a result of this force the cart accelerates with constant acceleration. The magnitude of the force that the cart exerts on the horse Select one: A.greater than the magnitude of f. B.equal to the magnitude of f. C.less than the magnitude of f. D.is zero newtons. E.cannot be determined without knowing the mass of the horse.

equal to the magnitude of f

Suppose a ball is thrown straight up and experiences no appreciable air resistance. What is its acceleration just before it reaches its highest point? Select one: A.slightly less than g B.zero C.slightly greater than g D.exactly g

exactly g

A bucket is being lowered by a rope with a constant downward acceleration. The tension in the rope must be equal to the weight of the bucket. Select one: True False

false

When is the average velocity of an object equal to the instantaneous velocity? Select one: A.always B.never C.only when the velocity is increasing at a constant rate D.when the velocity is constant E.only when the velocity is decreasing at a constant rate

when the velocity is constant

Suppose you are playing hockey on a new-age ice surface in which there is no friction between the ice and the hockey puck. You wind up and hit the puck as hard as you can. Just after the puck loses contact with your stick, the puck Select one: A.will speed up a little, and then slow down. B.will not slow down or speed up. C.will speed up a little, and then move at a constant speed. D.will start to slow down.

will not slow down or speed up

A stalled car is being pushed up a hill by three people, and it is moving at a constant speed. The net force on the car is Select one: A.in the same direction of the car's motion. B.in the opposite direction of the car's motion. C.zero. D.None of the above

zero