Physics Chapter 4 Test.

A sack of potatoes weighing 200 N falls from as airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration becomes

0m/s2

A 1-kg rock weighs 10 N is thrown straight upward at 20 m/s. Neglecting air resistance the net force that acts on it when it is halfway to the top of its path is?

10 N

The force of friction on a sliding object is 10 N. The Applied force needed to maintain a constant velocity is?

10 N

A push on a 1-kg brick accelerates it. Neglecting friction, equally accelerating a 10-kg brick requires

10 times as much force

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

10 times more than the force on the apple

The mass of a lamb that weights 110 N is about....?

11 kg

An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration due to gravity on this planet?

12 m/s2

A car has mass of 1000 kg and accelerates at 2 m/s2. What net force is exerted on the car?

2000 N

Nellie pulls on a 10-kg wagon with a constant horizontal force of 30 N. If there are no other horizontal forces, what is the wagons acceleration?

3.0 m/s2

A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time?

300m

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

6 N

If you double the net force of an object, you'll double it's?

Acceleration

Which has zero acceleration? An object

All of the above (At rest, moving in a constant velocity, in mechanical equilibruim)

Which has the greater mass? A pillow or a Automobile battery

An automobile battery

A heavy ball hangs by a string, with a second string attached to its bottom, A quick pull on the bottom string breaks the?

Bottom

You drive your car at a constant 60 km/h along the highway. You apply the breaks until the car slows to 40 km/h. If at that moment you suddenly release the breaks the car tends

Continue moving at 40 km/h

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

Eventually slides to a stop

The newton is a unit of?

Force

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

A heavy rock, and a light rock of the same size are falling through the air from a tall building. The one that encounters the greatest air resistance is the?

Heavy rock

When the bottom string is pulled slowly in the heavy-ball-and-strings demonstration tension?

In the top string is due to to your pull plus the weight of the ball

If an objects mass is decreasing while a constant force is applied to the object, the acceleration

Increases

A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is.

More

An object's weight is properly expressed in the units of?

Newtons

Strange as it may see, it is just as difficult, to accelerate a car on a level surface on the moon as it is here on Earth because?

The mass of the car is independent of gravity

When a constant and sustained upward force acts on a rocket, its acceleration increases mainly because?

The mass of the rocket decreases as fuel is burned

A feather and a coin will have equal accelerations when falling in a vacuum because?

The ratio of both the feather's and coin's weight to mass is the same

The force required to maintain a constant velocity for an astronaut in free space is equal to?

Zero

When a falling object has reached its terminal velocity, its acceleration is?

Zero

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

Zero

A boulder following a straight-line path at constant velocity has?

Zero acceleration

Recall Galileo's Leaning tower experiment. With negligible air resistance, a heavy and a light object fall.

all of the above

At equilibrium on a bathroom weighing scale, the downward pull of gravity on you is balanced by

an upward support force

Suzie skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration

decreases

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

g

A coconut and a birds feather fall from a tree through the air to the ground below. The force of air resistance is

greater on the coconut

If the mass of a cart is quickly loaded to have twice the mass while propelling the force remains constant, the carts acceleration

halves

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

inertia, mass, and volume(all of the above)

Two factors that greatly affect air resistance on falling objects are frontal area and

speed