Ch4 Physics Test Review

A 12-N falling object encounters 12 N of air resistance. The magnitude of the net force on the object is

0 N

A bowling ball weighs 20 N. When held at rest in your hands, the net force on the bowling ball is

0 N

When an object reaches terminal velocity, its acceleration is

0 m/s^2

An apple weighs 1N. The Net Force on the apple when it is in free fall is

1 N

A minivan has a mass of 2000 kg and accelerates at 2 meters per second squared. What is the magnitude of the force acting on the minivan?

4000 N

When a woman stands with two feet on a scale, the scale reads 470 N. When she lifts one foot, the scale reads

470 N

Accelerations are produced by

forces

If a truck has ten times the mass of a car and the two vehicles are pushed with an equal force, you would expect the acceleration of the truck to be

1/10 times that of the car

If shopping cart A has five times more mass in it than shopping cart B and the two carts are pushed with equal forces, you can expect the acceleration of shopping cart A to be

1/5 times that of shopping cart B

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is

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

How much force is needed to accelerate a 2.0 kg physics book to an acceleration of 6.0 m/s^2?

12 N

A toy box is dragged without acceleration in a straight line path across a level surface by a force of 13N. What is the frictional force between the toy box and the surface?

13 N

A girl pulls on a 7-kg wagon with a constant force of 14 N. What is the wagon's acceleration?

2 m/s^2

A jet has a mass of 30,000 kg. The thrust for each of the four engines is 15,000 N. What is the jet's acceleration when taking off?

2 m/s^2

Suppose the force of friction on a sliding object is 20 N. The force needed to maintain a constant velocity is

20 N

A tow truck exerts a force of 1000 N on a car, accelerating it at 0.5 m/s. What is the mass of the car?

2000 kg

If you pull horizontally on a desk with a force of 150 N and the desk doesn't move, the friction force must be 150 N. Now if you pull with 280 N so the desk slides at constant velocity, the friction force is

280 N

You pull horizontally on a 50 kg crate with a force of 250 N and the friction force on the crate is 100 N. The acceleration of the crate is

3 m/s^2

A jumbo jet cruises at a constant velocity when the total thrust of the engines on the jet is 35,000 N. How much air resistance acts on the jet?

35,000 N

A 10-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is

6 N

An object has a constant mass. A constant force on the object produces constant

acceleration

Suppose a particle is accelerated through space by a constant 10-N force. Suddenly the particle encounters a second force of 10-N in a direction opposite to that of the first force. The particle

continues at the speed it had when it encountered the second force

As a care package falls from a highflying stationary helicopter, its velocity increases and its acceleration

decreases

When the angle of an incline with a block resting on it increases, the normal support force

decreases

A block is at rest on an incline. The force of friction necessary to prevent the block from sliding increases when the incline angle is

increased

How does acceleration of an object change in relation to its mass? It is

inversely proportional

The acceleration produced by a net force on an object is

inversely proportional to the mass of the object, directly proportional to the magnitude of the net force, and in the same direction as the net force

If the force acting on a cart doubles, what happens to the cart's acceleration?

it doubles

Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration?

it halves

A rock is thrown vertically into the air. At the very top of its trajectory, the net force is

its weight

The reason a tennis ball and a solid steel ball will accelerate at the same time in the absence of air resistance is that

the ball with the larger force also has the larger mass

A heavy person and a light person parachute together and wear the same size parachute. Assuming they open their parachutes at the same time, which person hits the ground first?

the heavy person

A force of 5 N accelerates a mass of 5 kg at the rate of 1 m/s^2. The acceleration of a mass of 10 kg acted upon by a force of 10 N is

the same

Aunt Minnie throws a rock downward, and air resistance is negligible. Compared to a rock that is dropped, the acceleration of the rock after it is thrown is

the same

A tennis ball and a solid steel ball with the same diameter are dropped at same time. Which ball has the greater force acting on it?

the steel ball

A tennis ball and a solid steel ball with the same diameter are dropped at the same time. In the absence of air resistance, which ball has the greater acceleration?

they both have the same acceleration

A speeding truck locks its brakes and skids to a stop. If the truck's total mass were doubled, its skidding distance would be

twice as far

A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick, one would have to push

with 10 times as much force