Hasan Exam #2

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 in meters per second per second is

0

An object travels 8 meters in the first second of travel, 8 meters again during the second second of travel, and 8 meters again during the third second. Its acceleration in meters per second per second is

0

What is the acceleration of a car that maintains a constant speed of 100 km/hr for 10 seconds moving eastward?

0

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

0 Newtons

On a balanced see saw, a boy three times as heavy as his partner sits

1/3 the distance from the fulcrum

Ten seconds after starting from rest, an object falling freely downward will have a speed of about

100 m/s

A car has a mass of 1000 kg and accelerates at 1 meters per second per second. What is the magnitude of the net force exerted on the car?

1000 N

A baseball player bats a ball with a force of 1000 N. The ball exerts a reaction force against the bat of

1000 N.

A car accelerates at 2 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s?

15 seconds

If an object falling freely downward were somehow equipped with a speedometer on a planet where the acceleration due to gravity (g) is 20 meters per second per second, then its speed reading would increase each second by

20 m/s

A package falls off a truck that is moving at 30 m/s. In the absence of air resistance, the horizontal speed of the package just before it hits the ground is

30 m/s

Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration in meters per second per second?

4.0

A person is attracted toward the center of the Earth by a 500-N gravitational force. The force of attraction of the Earth toward the person is

500 N.

If a car increases its velocity from zero to 60 km/h in 10 seconds, its acceleration is

6 km/h per second

At one instant an object in free fall is moving downward at 50 meters per second. One second later its speed is about

60 m/s

An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the ground. If it instead flies into a 10 km/h headwind, its groundspeed is

90 km/h

The impulse-momentum relationship is a direct result of

Newton's 2nd law

If an object of constant mass experiences a constant net force, it will have a constant

acceleration

When you stand at rest on a pair of bathroom scales, the readings on the scales will always

add to equal your weight

A truly educated person is knowledgeable about

all of these

Science, art, and religion do not contradict one another because

all three have different domains

Suppose you're coasting on level ground 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

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

A skydiver steps from a helicopter and falls for 5 seconds before reaching her terminal velocity. During this 5-second interval, her acceleration

decreases

An open freight car rolls friction free along a horizontal track in a pouring rain that falls vertically. As water accumulates in the car, the car's speed

decreases

When an object falls through the air, its velocity increases and its acceleration

decreases

A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always

directed downward

When a train makes a curve, the wheel on the outside part of the curve must travel (relative to the inside wheel)

faster

The newton is a unit of

force

A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the

force the glove exerts on the ball

A car that travels twice as fast as another when braking to a stop will skid

four times as far

A kilogram is a measure of an object's

inertia at rest, mass

Whenever the net force on an object is zero, its acceleration

is zero

An object maintains its state of motion because it has

mass

Which of the following is not a vector quantity?

mass

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much

mass, volume, inertia

Compared to the force that brings a small car to a stop, the force required to bring a heavy truck traveling at the same speed to a stop

may be less and may be more.

In science, facts

may change.

A torque acting on an object tends to produce

rotation

Two factors that greatly affect air resistance on falling objects are the

size and speed of the object

Galileo's use of inclined planes allowed him to effectively

slow down the acceleration of free fall

Since each rolling wheel of a railroad train is tapered, the narrow part of the wheel has a tangential speed that is

smaller than that of the wide part

Strange as it may seem, it is just as hard to accelerate a car on the moon as it is to accelerate the same car on Earth. This is because

the mass of the car is independent of gravity

A sheet of paper can not be withdrawn from under a container of milk without toppling it if the paper is drawn very slowly. This best demonstrates that

the milk carton has inertia

If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity,

the object eventually slides to a stop

An object of mass 30 kg on Earth. A second object has a mass of 30 Kg on the moon. Which has the greater weight?

the one on Earth

A Mack truck and a Volkswagen traveling at the same speed collide head-on. The impact force is

the same for both

Suppose a gun were made of a strong but very light material. Suppose also that the bullet is more massive than the gun itself. For such a weapon

the target would be safer than the shooter.

An apple weighs 1 N. The net force on the apple when it is in free fall is

1 N

Exert 2 N force for a distance of 1 m in 2 s and you deliver a power of

1 W

The mass of a pet turtle that weighs 10 N is about

1 kg

The average speed of a horse that gallops a distance of 15 kilometers in a time of 30 minutes is

30 km/h

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is

9.8

If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it forcefully downwards, its acceleration (in the absence of air resistance) will be

9.8 meters per second per second

Action and reaction forces comprise the parts of

a single interaction

Disregarding air resistance, objects fall with constant

acceleration

Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom

at the same time as the light block

A heavy object and a light object are dropped at the same time from rest in a vacuum . The heavier object reaches the ground

at the same time as the lighter object

An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would

double

A large and a small person wish to parachute at equal terminal velocities. The larger person will have to

get a larger parachute

When a scientist is dishonest and reports false information, he or she

gets no second chance in the scientific community.

A clerk can lift containers a vertical distance of 1 meter or can roll them up a 2 meter-long ramp to the same elevation. With the ramp, the applied force required is about

half as much

If you push an object half as far while applying the same force you do

half the amount of work

An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, its acceleration

halves

An object following a straight-line path at constant speed

has zero acceleration

A skydiver's terminal velocity will be greatest if she falls

head first

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

heavier object

Science is a body of knowledge that goes back to

humankind's beginnings

A heavy truck and a small truck roll down a hill. Neglecting friction, at the bottom of the hill, the heavy truck will have greater

momentum

What does an object have when moving that it never has when at rest

momentum

Horses that move with the slowest linear speed on a merry-go-round are located

near the center

An industrial flywheel has a greater rotational inertia when most of its mass is

nearest the rim

A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of

power

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the

road

A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because

the mass of the rocket decreases as fuel is burned.

The attraction of a person's body toward the Earth is called weight. The reaction to this force is

the person's body pulling on the Earth

While a car travels around a circular track at constant speed its

velocity and acceleration are changing

The two measurements necessary for calculating average speed are

velocity and distance

As an object freely falls downward, its

velocity increases