PHY-1025-Test 3

Two billiard balls having the same mass and speed roll toward each other What is their combined momentum after they meet?

0

An apple weighs 1 N. When the apple is falling down with no air resistance, the net force on the apple is

1 N

A piece of putty moving with 1 kg m/s of momentum strikes to a heavy bowling ball that is initially a rest. After the putty sticks to the ball, both move with a combined momentum of

1 kg m/s

A 5 kg shark swimming at a speed of 1 m/s swallows an absent-minded 1 kg fish swimming toward it at 4 m/s. The speed of the shark after this meal is...

1/6 m/s

What is the weight of a 10 kg bag of apples?

100 N

How many watts of power do you expend when you exert a force force of 50 N that moves a crate 8 m in a time interval of 4s?

100 W

A car experience a 2000 N net force and accelerates at 2 meters per second per second. What is the mass of the car?

1000kg

A car that was moving at 50km/h skids 15 m with locked brakes. How far will the car skid with locked breakes if it was moving at 150km/h

135m

what is the magnitude of the impulse on an 8 kg ball rolling at 2 m/s when it bumps into a pillow and stops

16 N

A 2 kg mass has 40 J of potential energy with respect to the ground. Approximately how high is it above the ground?

2 m

A single engine airplane is taking off with an acceleration of 0.25 m/s/s. If its engine thrust is 500 N, what is the mass of the plane?

2000 kg

The second floor of a house is 6 m above the street level. How much work is required to lift a 400 kg refrigerator to the second- story level?

24000 J

A 4 kg ball has a momentum of 12 kg m/s. What is the ball's speed?

3 m/s

A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is

3000 N

A child tosses a 1 kg book across the room at a speed of 3 m/s. what is the kinetic energy of the book?

4.5 J

A bow is drawn so that it has 40 J of potential energy. When fired, the arrow will ideally have a kinetic energy that is

40 J

What is the kinetic energy of an 800 kg car moving at 1 m/s speed?

400 J

A diver who weighs 400 N steps off a diving board that is 10 m above the water. The Diver hits the water with kinetic energy of

4000 J

A skydiver of mass 100 kg experiences air resistances of 500 N, and an accelerations of

5 m/s/s

The student shown in the figure below uses a pulley to lift a 50 N box. what is the force required to lift the box completely off the ground?

50 N

If an input of 100 J in a pulley system increases the potential energy of a load by 60 J, what is the efficiency of the system

60 %

What is the net force on a cart that is pulled to the right with 100 N and to the left with 30 N

70 N to the right

A moves 3 times as fast as another identical car. Compared to the slower car, the faster car has

9 times the KE

Which has zero acceleration? An object

A). at rest. B). moving at constant velocity C). in mechanical equilibrium D). all of these

If an object's mass is increasing while a constant force is applied to the object, the acceleration...

Decreases

Whereas impulse involves the time that a force a force acts, work involves the

Distance that a force acts

A Machine cannot multiply

Energy

Your friend pushes a lawnmower 4 m, exerting 20 N force. You push the lawnmower only 1 m, but exerts 40 N force.

Friend does 40 J more work than you do

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

Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a tower, they reach the ground at the same time, but the heavier one has greater

Momentum

A woman carries a heavy box across a room at a constant speed. How much work does she do on the box while walking?

None

A light aluminum ball and heavy lead ball of the same size are allowed to roll down an incline. When they are halfway down the incline, they will have identical

None of the above choices

The maximum acceleration of a car while towing an identical second car compared to its acceleration with no car in tow, is

One Half

As a ball falls, the action force is the pill of Earth on the ball. The reaction force is the

Pull of the ball's mass on the Earth

A Mack truck and Volkswagen traveling at the same speed have a head-on collision. The Vehicle that the greater force will be the...

Same force for both

The ball rolling down an incline has its maximum potential energy at?

The Top

An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the..

arrow's push against the bowstring.

A player hits a ball with a bat. The action force is that impact of the bat against the ball. The reaction to this force is the

force that the ball exerts on the bat

A rifle recoils while firing a bullet. the speed of the rifle's recoil is small because the...

rifle has much more mass than the bullet

Compared to falling on a stone floor, a wine glass may not break when it falls on carpeted floor because ..

stopping time is longer on the carpet.

Earth pulls on the moon. Similarly the moon pulls on Earth, evidence that

these two pulls comprise of an action -reaction pair.

To catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because the ...

time of impact is increased

If an object is raised twice as high, its potential energy will be

twice as much

If you find that twice as much work is needed to perform a task but it takes twice as much time, the amount of power required is

unchanged.