Physics Test 2

320N

If you need to tighten a bolt with 80 Nm of torque using a wrench with a handle that is 25 cm from the axis of the bolt, how much force do you need to apply when turning the wrench?

1m/s

A 1kg glider and a 3kg glider both slide toward each other at 2m/s on an air track. They collide and stick. The combined mass moves at _______

80J

A 2kg mass is held 4m above the ground. What is the approximate potential energy of the mass with respect to the ground?

momentum

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

momentum

A heavy truck and a light truck roll down a hill. Neglecting friction, at the bottom of the hill, the light truck will have less _______

40%

A jack system will increase the potential energy of a heavy load by 400J and generate 600J of heat with a work input of 1,000J. The efficiency of the jack system is _______

A & C

A longer cannon barrel is advantageous because it increases _______

Ring

A ring, a disk, and a solid sphere begin rolling down a hill together. the one to reach the bottom last is the

always false

A simple level, properly arranged, is capable of multiplying work input. T or F

Art has 1/2 the mass of Bart

Acrobat Bart at the circus drops vertically onto the end of a see-saw, with his partner Art equidistant from the fulcrum at the other end. Art is propelled straight upward a distance twice that of Bart's dropping distance. Neglecting inefficiencies we see _______

Rotating (sharp turn in a car)

Centrifugal forces are an apparent reality that is

half the power

Doing twice the usual work on an object in four times the usual time requires _______

A & B (increase length of string and spin the ball faster)

How can you increase angular momentum of a ball spinning on a string?

5s

How long will it take to stop a 1500 kg car moving at 20m/s with a braking force of 6,000N?

directed toward the center of the curve

If a car travels in a circle with constant speed, its net force on the car is ___

that changes as a person bends over

The center of mass of a human body is located at a point

Above its place of support

The leaning tower of pisa doesn't topple over because its center of gravity is __

5m

To do 10J of work pushing a crate using 2N of force, you will need to push the crate

-3m/s

Two billiard balls of the same mass roll straight toward each other. The first has a velocity of +5m/s and the second has a velocity of -3m/s. After colliding, the first ball has a velocity of _______

heat

When a car is braked to a stop, its kinetic energy is transformed to _______

remains the same (bc initial momentum mist equal final momentum)

When a twirling ice skater brings her arms inward, her angular momentum

60km/h

Which has a greater kinetic energy , a car traveling at 30km/hr or a car of half the mass traveling at 60km/hr

100 to 70

Which requires the most amount of work by the brakes of a car?

Quadrouples

Your pet hamster sits on a spinning record player. If the angular speed of the record player doubles and he moves to a point twice as far from the center, then his linear speed (assuming he doesn't fly off the record player and onto the floor, causing PETA and SPCA to come after you)

highest, farthest from your hand

an upright broom is easier to balance when the heavier end is