Physics Ch. 2

When a baseball player hits a ball with a force of 1000 N, the ball exerts force on the bat of A. more than 1000 N. B. 1000 N. C. less than 1000 N.

B. 1000 N.

When a falling object has reached its terminal velocity, its acceleration is A. constant. B. zero. C. g

B. zero.

A Honda Civic Hybrid weighs about 2650 lb . 1. Calculate the weight of the car in newtons. (Note: 0.22 lb =1N). 2. Calculate the mass of the car in kilograms. (Note: 1 kg on Earth's surface has a weight of 10 N).

1. W = 1.2×10^4 N 2. m= 1200kg

A 10-N falling object encounters 10 N of air resistance. The net force on it is A. 0 N. B. 4 N. C. 10 N. D. 6 N.

A. 0 N.

When a 10-kg block is simultaneously pushed eastward with 20 N and westward with 15 N, the acceleration of the block is A.0.5 m/s2 east. B.0.5 m/s2 west. C.0.5 m/s2 east-west. D.None of the above.

A. 0.5 m/s2 east.

A commercial jet has a mass of 5,000 kg and the thrust of its engine is 10,000 N. The acceleration of the jet when taking off is A. 2 m/s2. B. 0.5 m/s2. C. 1 m/s2. D. 4 m/s2.

A. 2 m/s2.

A karate chop breaks a board with a blow of 3000 N. The force that acts on the hand during this event is A. 3000 N. B. more than 3000 N. C. less than 3000 N.

A. 3000 N.

A skydiver who weighs 500 N reaches terminal velocity at 90 km/h. The air resistance on the skydiver is A. 500 N. B. 250 N. C. 90 N. D. 410 N.

A. 500 N.

The auto in the sketch moves forward as the brakes are applied. A bystander says that during the interval of braking, the auto's velocity and acceleration are in opposite directions. Do you agree or disagree? A. Agree. Acceleration (slowing the car) is opposite to velocity (the direction the car is moving). B.Disagree. Acceleration (slowing the car) is the same to velocity (the direction the car is moving).

A. Agree. Acceleration (slowing the car) is opposite to velocity (the direction the car is moving).

A Mack truck and a Mini Cooper traveling at the same speed collide head-on. The vehicle to undergo the greatest change in velocity will be the A. Mini Cooper. B. Mack truck. C. same

A. Mini Cooper.

Arnold Strongman and Suzie Small have a tug-of-war on a polished floor. Arnold wears socks and Suzie wears gym shoes. The likely winner is A. Suzie. B. Arnold. C. neither, a tied score D. no basis for predicting

A. Suzie.

Action and reaction forces comprise the parts of A. a single interaction. B. two interactions. C. multiple interactions.

A. a single interaction.

A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration A. decreases. B. increases. C. remains unchanged regardless of air resistance.

A. decreases.

Inside the interior of a truck that moves at constant velocity is a package that drops from the midpoint of the ceiling. The package hits the floor A. exactly below the midpoint of the ceiling. B. ahead of the midpoint of the ceiling. C. behind the midpoint of the ceiling. D. more information is needed none of the above

A. exactly below the midpoint of the ceiling.

A ball rests in the middle of a cart. When you quickly jerk the cart forward, the ball A. hits the back of the cart. B. hits the front of the cart. C. all, depending on how quickly D. the cart is pulled. E. remains in the middle of the cart.

A. hits the back of the cart.

A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension A. increases. B. remains the same. C. decreases.

A. increases.

If you are carrying a heavy bag of groceries and bang your hand against the wall, the concept that best explains why you are hurt is A. inertia. B. acceleration. C. resistance. D. gravity.

A. inertia.

When dishes remain on a table when you yank the tablecloth beneath them, you're demonstrating A. inertia. B. friction. C. F = 0. D. constant motion.

A. inertia.

A ball is thrown vertically upward. Because of air resistance, its speed when returning to its starting level compared with its initial speed is A. less. B. the same. C. more.

A. less.

A falling object that has reached its terminal speed continues to gain A. neither B. acceleration. C. both D. speed

A. neither

A falling object that reaches terminal velocity continues to have A.speed. B.a nonzero net force. C.acceleration. D.All of the above.

A. speed.

A roller coaster car at an amusement park carrying 1 passenger takes 3 min to make its ride from start to finish. Neglecting friction, a car with 5 passengers would take A. the same time. B. more time. C. less time

A. the same time.

A force of 1 N accelerates a 1-kg mass at 1 m/s2. The acceleration of a 2-kg mass acted upon by a force of 2 N is A. the same. B. twice as much. C. half as much.

A. the same.

The force required to maintain an object at a constant velocity in free space is equal to A. zero. B. the mass of the object. C. the force required to stop it. D. the weight of the object.

A. zero.

The net force on any object moving at constant velocity is A. zero. B. equal to its weight. C. less than its weight. D. 10 meters per second squared.

A. zero.

A hockey puck slides across a frozen pond. If ice friction and air resistance are neglected, the force needed to keep the puck sliding at constant velocity is A. equal to the weight of the puck. B. 0 N. C. the weight of the puck divided by the mass of the puck. D. the mass of the puck multiplied by 10 m/s2. E. none of the above

B. 0N

A tow truck exerts a force of 3000 N on a car that accelerates at 2 m/s2. The mass of the car must be A. 1000 kg. B. 1500 kg. C. 3000 kg. D. 500 kg.

B. 1500 kg.

Two people, one twice as massive as the other, attempt a tug-of-war with 12 m of rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of A. 6 m. B. 4 m. C. 3 m. D. 5 m.

B. 4 m.

A block is dragged at constant velocity across a level surface by a force of 6 N. What is the force of friction between the block and the surface? A. less than 6 N B. 6 N C. more than 6 N

B. 6 N

A 10-N falling object encounters 4 N of air resistance. The net force on it is A. 10 N. B. 6 N. C. 4 N. D. 0 N.

B. 6 N.

When you toss a rock straight upward, which is no longer present at the top of its path? A.Mass. B.Speed. C.Acceleration. D.All of the above.

B. Speed.

If the mass of an object does not change, a constant net force on the object produces constant A. velocity. B. acceleration. C. both D. none of the above

B. acceleration.

A friend says that the heavyweight champion of the world cannot exert a force of 50 N on a piece of tissue paper with his best punch. The tissue paper is held in midair, no wall, no tricks. You A. disagree, for a good punch easily delivers this much force. B. agree that it can't be done. C. have reservations about this assertion.

B. agree that it can't be done.

A player hits a ball with a bat. If one part of the interaction is the bat against the ball, the other part is the A. weight of the ball. B. ball against the bat. C. grip of the player's hand against the ball. D. air resistance on the ball.

B. ball against the bat.

If an object falls with constant acceleration, the velocity of the object must A. continually decrease. B. continually change by the same amount each second. C. continually change by varying amounts, depending on its speed. D. be constant also.

B. continually change by the same amount each second.

A given net force propels an object along a straight-line path. If the net force were doubled, its acceleration would A. stay the same. B. double. C. quadruple. D. be half. E. none of the above

B. double.

An elephant and a feather fall from a tree through the air to the ground below. The force of air resistance is greater on the A. same on each. B. elephant. C. feather.

B. elephant.

You toss a ball upward where air resistance is negligible. After the ball leaves your hand the force on it A. first acts upward and then downward after it reaches the top. B. is the single force due to gravity, always directed downward. C. gradually decreases until the ball reaches the top of its path. D. none of the above.

B. is the single force due to gravity, always directed downward.

A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. Air resistance just before they hit is actually greater for the A. same for both B. lead-filled ball C. regular ball.

B. lead-filled ball

A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the A. same for both B. lead-filled ball. C. regular ball.

B. lead-filled ball.

A sheet of paper can be pulled from beneath a box of cereal without toppling it if the paper is jerked quickly. This best demonstrates that A. there is an action-reaction pair of forces. B. the box has inertia. C. the box has no acceleration. D. gravity tends to hold the box secure.

B. the box has inertia.

A rock is thrown vertically upward. At the top of its straight-line path, its velocity is A. greater than 10 m/s. B. 10 m/s. C. 0 m/s. D. between 0 m/s2 and 10 m/s2.

C. 0 m/s.

A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration is A. infinite. B. 5 m/s2. C. 0 m/s2. D. 10 m/s2.

C. 0 m/s2.

A 10-kg block is pushed across a horizontal surface with a horizontal force of 20 N against a friction force of 10 N. The acceleration of the block is A. 10 m/s2. B. 5 m/s2. C. 1 m/s2. D. 2 m/s2

C. 1 m/s2.

A 1-kg ball is thrown straight up at 10 m/s. Neglecting air resistance, the net force that acts on the ball when it is half way to the top of its path is A. 5 N. B. 1/2 N. C. 10 N. D. 7.5 N. E. 1 N.

C. 10 N.

A 100-kg vehicle accelerates at 1 m/s2 when the net force on it is A.1 N. B.10 N. C.100 N. D.1000 N

C. 100 N.

A 10-kg block is pushed across a friction-free horizontal surface with a horizontal force of 20 N. The acceleration of the block is A. 1 m/s2. B. 10 m/s2. C. 2 m/s2. D. 5 m/s2.

C. 2 m/s2.

A 10-kg block is pushed across a horizontal surface with a horizontal force of 30 N against a friction force of 10 N. The acceleration of the block is A. 1 m/s2. B. 10 m/s2. C. 2 m/s2. D. 5 m/s2.

C. 2 m/s2.

A person is attracted toward the center of Earth by a 500-N gravitational force. The force of attraction of Earth toward the person is A. very, very small. B. very, very large. C. 500 N

C. 500 N

If gravity between the Sun and Earth suddenly vanished, Earth would continue moving in A. an outward spiral path. B. an inward spiral path. C. a straight-line path. D. a curved path.

C. a straight-line path.

When you step off a bus moving at 10 m/s, your horizontal speed when you meet the ground is A. greater than 10 m/s. B. zero. C. about 10 m/s. D. less than 10 m/s but greater than zero.

C. about 10 m/s.

Newton's second law directly involves A. velocity. B. speed. C. acceleration. D. none of the above

C. acceleration.

A heavy object and a light object in a vacuum are dropped at the same time from rest. The heavier object reaches the ground A. sooner than the lighter object. B. later than the lighter object. C. at the same time as the lighter object.

C. at the same time as the lighter object.

A given net force propels an object along a straight-line path by a force. If the mass were doubled, its acceleration would A. double. B. quadruple. C. be half. D. stay the same. E. none of the above

C. be half.

Earth pulls on the Moon. Similarly the Moon pulls on Earth, evidence that A. Earth and Moon pull on each other. B. Earth's and Moon's pulls comprise an action-reaction pair. C. both

C. both

When an object falls through the air and gains velocity, the net force actually A. remains the same whether in air or in a vacuum. B. increases. C. decreases.

C. decreases.

A ball tossed vertically upward reaches its highest point and then falls back to its starting point. During this up-and-down motion the acceleration of the ball is always A. opposite its velocity. B. directed upward. C. directed downward. D. in the direction of motion

C. directed downward.

When you toss a coin straight up, it moves upward, turns around, and drops. During this time the acceleration of the coin is A. zero throughout its up and down motion. B. first decreasing, then increasing. C. downward and constant. D. upward and constant.

C. downward and constant.

Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the rock tends to A. continue in a circular path. B. spiral inward. C. follow a straight-line path. D. fall straight downward.

C. follow a straight-line path.

A player catches a ball. Consider the action force to the ball against the player's glove. The reaction is the A. muscular effort in the player's arms. B. player's grip on the glove. C. force of the glove on the ball. D. friction of the ground against the player's shoes.

C. force of the glove on the ball.

Two objects of the same size but unequal weights are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the A. lighter object. B. both hit at the same time. C. heavier object.

C. heavier object.

If an object's mass decreases while a constant force acts on it, the acceleration A. decreases. B. remains the same. C. increases. D. will be zero.

C. increases.

How many forces act on an upwardly tossed coin when it gets to the top of its path? A. two; gravity and the force in the coin itself B. three; gravity, the coin's internal force, and a turnaround force C. one; the force due to gravity

C. one; the force due to gravity

As a ball falls, the action force is the pull of Earth's mass on the ball. The reaction force is the A. acceleration of the ball. B. air resistance acting against the ball. C. pull of the ball's mass on Earth. D. nonexistent.

C. pull of the ball's mass on Earth.

After a ball tossed upward leaves your hand, the force of gravity on it A. no longer acts. B. gradually diminishes. C. remains constant. D. changes direction. E. gradually increases.

C. remains constant.

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the A. tires. B. engine. C. road. D. air.

C. road.

A Mack truck and a Mini Cooper traveling at the same speed collide head-on. The collision force is greatest on the A. Mini Cooper. B. Mack truck. C. same

C. same

Arnold Strongman and Suzie Small each pull on opposite ends of a rope in a tug-of-war. The greatest force on the rope is exerted by A. Suzie. B. Arnold. C. same

C. same

A car traveling at 100 km/h strikes an unfortunate bug that splatters on the windshield. The force of impact is greater on the A. bug. B. car. C. same for both

C. same for both

The air resistance of falling is greatly affected by an object's frontal area and A. weight. B. mass. C. speed.

C. speed.

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to a state of zero acceleration first? A. the heavy man B. both should at the same time C. the light woman D. not enough information

C. the light woman

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is A. 5 times as much as the force on the 1-kg book. B. zero. C. the same as the force on the 1-kg book. D. 10 times as much as the force on the 1-kg book.

D. 10 times as much as the force on the 1-kg book.

A 10-N block and a 1-N block lie on a horizontal frictionless table. To push them with equal acceleration, we would have to push with A. one-tenth as much force on the heavier block. B. 10 squared or 100 times as much force on the heavier block. C. equal forces on each block. D. 10 times as much force on the heavier block.

D. 10 times as much force on the heavier block.

A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick requires the force to be A. one-tenth the amount. B. 100 times as much. C. just as much. D. 10 times as much. E. none of the above

D. 10 times as much.

A jumbo jet has a mass of 100,000 kg. The thrust for each of its four engines is 50,000 N. The acceleration of the jet when taking off is A. 4 m/s2. B. 1 m/s2. C. 0.5 m/s2. D. 2 m/s2.

D. 2 m/s2.

A car has a mass of 1000 kg and accelerates at 2 m/s2. What is the magnitude of the force exerted on the car? A. 1500 N B. 500 N C. 1000 N D. 2000 N

D. 2000 N

Both ends of a piece of rope are pulled by two people in a tug-of-war. If each pulls with a 400-N force, the tension in the rope is A. 0 N. B. 600 N. C. 800 N. D. 400 N.

D. 400 N.

Earth moves about 30 km/s relative to the Sun. When you jump upward in front of a wall, the wall doesn't slam into you at 30 km/s because the wall A. has negligible inertia compared with the Sun. B. has too little gravity to influence you. C. moves in the opposite direction to you. D. and you move at the same horizontal speed, before, during, and after your jump.

D. and you move at the same horizontal speed, before, during, and after your jump.

An archer shoots an arrow. If the action force is the bowstring on the arrow, the reaction is the A. friction of the ground on the archer's feet. B. air resistance on the bow. C. weight of the arrow. D. arrow's push on the bowstring. E. grip of the archer's hand on the bow.

D. arrow's push on the bowstring.

Suppose you're coasting in a car at 60 km/h and apply the brakes until you slow to 40 km/h. When you suddenly release the brake, the car tends to A. decrease in speed whether B. other forces act or not. C. momentarily regain its higher initial speed. D. continue moving at 40 km/h in the absence of forces.

D. continue moving at 40 km/h in the absence of forces.

A space probe in remote outer space continues moving A. in a curved path. B. due to gravity. C. because a force acts on it. D. even though no force acts on it.

D. even though no force acts on it.

A girl pulls on a 10-kg wagon with a constant force of 30 N. What is the wagon's acceleration? A. 300 m/s2 B. 10 m/s2 C. 0.3 m/s2 D. 30 m/s2 E. 3.0 m/s2

E. 3.0 m/s2

A rocket of mass 150000 kg undergoes an acceleration of 1.2 m/s2 . Find the net force acting on it.

F= 1.8*10^5 N

A simple rearrangement of Newton's second law gives Fnet=ma. Find a net force that is needed to give a 11-kg package an acceleration of 6.8 m/s2 . (Note: The units kg⋅m/s2 and N are equivalent.). Force= ma

F= 75N

A business jet of mass 26000 kg takes off when the thrust for each of two engines is 40000 N . Find its acceleration.

a= 3.1 m/s^2

In the textbook acceleration is defined as a=Δv/Δt. Use this formula to find the acceleration of a cart on an inclined plane that gains 6.0 m/s each 1.7 s . acceleration= f/m

a= 3.5m/s^2