Physics - Chapter 4

A model airplane traveling north at 4 km/h in a 3-km/h crosswind (at right angles) has a ground speed of

5 km/h

Toss a ball straight up in the air at 30 m/s and without air resistance its speed will again be 30 m/s in

6 seconds

A ball tossed at an initial angle of 25° will have the same range as a ball tossed at the same speed at which of the following angles?

65 degrees

A motorcycle undergoes acceleration when

A nonzero net force acts on it

If action is a foot kicking a soccer ball, the reaction is an equal force on the

foot

An object with a mass of 1 kilogram on Earth (1)

has the same mass on the moon

When you slide a coin against another coin at the edge of a table, both coins will

hit the floor at the same time

A ball thrown off a cliff will fall 5 meters below its original straight-line trajectory when it is thrown

horizontally

When you jump vertically upward, strictly speaking, you cause earth to

move downward

In the absence of air resistance, the horizontal component of velocity for a baseball tossed across a field

not changed

The pressure that your book exerts against a tabletop is greater when you place it(on it's side, on it's back or on it's corner.

on it's corner

A cart is pushed and undergoes a certain acceleration. If the force is held constant and the mass of the cart doubles, its acceleration would be

one-half

If a 10-kg rock and 5-kg rock are dropped from the same height, at the same time, and in the absence of air resistance, then they will fall

same acceleration

When you toss a rock straight upward, which is no longer present at the top of its path?

speed

what is a vector quantity?

speed and direction

A boulder falls due to gravity. The reaction to the force on the boulder is

the boulder pulling up on Earth

You are standing at rest and begin to walk forward. What force pushes you forward?

the force of the ground on your feet

The reason a 10-kg rock falls no faster than a 5-kg rock in free fall is that

the force/mass ratio is the same for both

The force that propels a heavy truck along a highway is provided by

the highway pushing back on the wheels of the truck

A cart is pushed and undergoes a certain acceleration. It it were pushed with twice the force while its mass doubles, its acceleration would be

the same

Earth pulls on the Moon with a certain force. Relative to this force, the pull of the moon on earth is

the same

When a net force acts on an object, its acceleration depends n the object's

mass

When no air resistance acts on a projectile, its horizontal acceleration is

0

Use Newton's second law to answer this question: The acceleration of a vertically thrown ball at the top of its path is

10 m/s/s

Use Newton's second law to answer this question: The acceleration of a vertically thrown ball at the top of its path is

10 m/s2

The force of gravity acting on a 2-kg melon is

20 N

Each of the weight .....

40/ 9 m/s2

A projectile has equal horizontal and vertical components when it travels at

45 degrees

An elevator is being lifted at a constant speed by a steel cable attached to an electric motor. There is no air resistance, nor is there any friction between the elevator and the walls of the elevator shaft.

Equal to the force of gravity

In a force diagram .....

N

If a constant net force to the right is applied to a couch on a frictionless surface

The couch will have a constant acceleration to the right

A horse is hitched to a wagon. Which statement is correct?

The force that the horse exerts on the wagon is just as strong as the force that the wagon exerts on the horse.

A lead-filled tennis ball and a regular tennis ball are dropped from the top of a tall building at the same time. Air drag does affect motion. Which reaches the ground first?

The lead-filled one

A Kitten and a tiger .....

Tiger

A kitten and a tiger .....

Tiger

The force of air friction (air drag) against a falling sack of potatoes

acts upward. increases with increased area. increases with increased speed

When your mass increases, your weight

also increases

The amount of air resistance that acts on a wingsuit flyer (and a flying squirrel) depends on the flyer's

area and speed

A math book and a physics book are tied together with a length of string. With the string taut, one book is pushed off the edge of a table. As it falls, the other book is dragged horizontally across the table surface. With no friction, acceleration of the books is

between 0 and gravity

In free fall, the net force is .....

constant

Newton's concept of motion said that the natural state of an object was

constant velocity

As mass is added to a pushed object, its acceleration

decreases

In the absence of air resistance, the vertical component of velocity for a baseball tossed across a field

decreases then increases

When no air resistance acts on a fast-moving baseball, its acceleration is

downward gravity

When a squid pushes against water, the squid moves forward because the water

exerts a net forward force

Relative to the ground, an airplane gains speed when it encounters wind from behind, and loses speed when it encounters wind head-on. When it encounters wind at a right angle to the direction it is pointing, its speed relative to the ground below

increases

When you increase the net force on a shopping cart its acceleration

increases

During each second of free fall, the speed of an object

increases by the same amount

Mass is most closely related to

inertia

For a given force, acceleration and mass are

inversely proportional to each other

Whenever one object exerts a force on a second object, the second object exerts a force on the first that

is opposite in direction, is equal in magnitude, occurs at the same time.

An object will accelerate when

it is pushed or pulled with a net force

When we say that 1 kilogram weighs 10 N, we mean that

it's true at Earth's surface

A tennis ball filled with lead and a regular tennis ball are dropped from the top of a tall building at the same time. Both encounter air resistance. Which reaches the ground first?

lead-filled

A lead-filled tennis ball and a regular tennis ball are dropped from the top of a tall building. Air drag does affect motion. The ball that experiences the greater amount of air drag is the

lead-filled one

A 20-N object falling with 5 N of air resistance has an acceleration (less than,greater than or equal to gravity)

less than gravity

Air resistance on a projectile has no effect on its

mass

A force is a push or pull that is required to change the

the state of motion of an object

The component of velocity that changes for a projectile in the absence of air resistance is

vertical

An object with a mass of 1 kilogram on Earth (2)

weighs less on the moon

The force of friction between two surfaces can act

whether or not the surfaces move relative to each other

For a pair of vectors at right angles to each other, the resultant

will be larger