Physical Science Test 3 Ch 5 HW

A bow is drawn so that it has 40 jewels of potential energy. When the arrow is fired its kinetic energy is ideally...?

40 jewels

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

4 times as far

You are driving down the highway and a love bug splatters onto your wind shield. Which undergoes the greater force of impact?

Both the same

When a simple machine multiplies force it decreases...?

Distance moved

The most underlying feature of machines is...?

The conservation of wnergy

A dog and a mouse run along the same road with the same kinetic energy. The faster runner is the...?

The mouse

When a 100 kg astronaut ejects 0.5 kg of gas at a speed of 50 meters per second from her propulsion pistol her recoil speed is...?

0.05

A 0.5 kg blob of clay moving at 2 meters per second slams into a 4 kg blob at rest. The speed of the two blobs stuck together after colliding is about...?

0.25

A rifle of mass two kg is horizontally suspended by a pair of strings so that recoil can be measured. The rifle fires a bullet of mass 1/100 kg at a speed of 200 m/s. The recoil velocity of the rifle is about...?

1 m/s

The force of a falling Apple hitting depends on...?

1 the time of contact with the ground 2 wether or not the apple bounces 3 the speed of the Apple just before t hits

Two identical freight roll without friction towards each other on a level track. One car rolls at 2 m/s and the other rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of...?

1/2

A 1 kg glider an a 2 kg glider both slide towards each other at 1 m/s on an air track. They collide and stick, the combined gliders move at...?

1/3 m/s

A car moves 4 times as fast as another identical car. Compared with the slower car, the faster car has..?

16 times kinetic energy

A 2 kg mass that weighs 20 newtons has 50 jewels of potential energy relative to the ground. What is its height?

2 m

When the input of a piston of a hydraulic press is depressed 20 cm the output piston is observed to move 1 cm. an input force of 1 Newton can raise no more than...?

20 newtons

A 2500 Newton pile driver ram falls 10 meters and drives a post 0.1 meters into the ground. The average force on the post is...?

250,000 newtons

Two identical arrows one with twice the speed of the other are fired into a bail of hay. The faster arrow will penetrate the bail...?

4 times as far as the slow arrow

Using 1000 jewels of work a toy elevator is raised from the ground floor to the second floor in 20 seconds. How much power does the elevator use?

50 watts

A jack system will increase the potential energy of a heavy load by no more than 1000 jewels of a work I put of 2000 jewels. The efficiency of the jack system is at most...?

50%

In raising a 5000 Newton piano with a pulley system for ever 1 meter of rope pulled down the piano rises 0.1 meters. Ideally this means the force needed to lift the piano is...?

500 newtons

A boxer punches a sheet of paper in mid air from rest to a speed 40 m/s in 0.05 seconds. If the mass of the paper is 0.01 kg the force of the punch on the paper is...?

8 newtons

A 2 gram mass weighs 20 newtons and is held 4 meters above the ground. It's potential energy relative to the ground is...?

80 Jewels

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, the contact time is about 10 times more than a stiff legged landing, and the average force you body experiences is reduced by...?

About 10 times

A sand bag in outer space moves at 3 m/s when it collided and sticks to a half as massive sand back initially at rest. Compared with the kinetic energy of the moving sand bag before the collision the kinetic energy of the coupled sand bags after the collision...?

Are 2/3

Which requires more work? Lifting a 50 kg sack vertically two meters or lifting a 24 kg sack vertically 4 meters?

Both require the same

Freddy frog drops vertically from a tree onto a horizontal moving skateboard. Immediately after landing on the skateboard, Freddy's speed...?

Decreases

A moving object has...?

Energy, speed, momentum, and velovity

The force that accelerates a rocket in outer space is exerted on the rocket by the...?

Exhaust gasses

Which of these forms of energy is not renewable?

Fossil fuel power

A clerk can lift containers of vertical distance one meter, or roll them up a two meter long ramp to the same elevation. With the he ramp, the applied force needed is...?

Half as much

Compared to a recoiling rifle the bullet that is fired has a greater...?

Kinetic energy

If a charging rhino has momentum it must also have...?

Kinetic energy

A ball is projected into the air with 900 jewels of kinetic energy that is transformed to potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance its kinetic energy is...?

Less than 900 jewels

A golf ball is thrown at and bounces backward from a massive bowling ball that is initially at rest. After the collision compared to the golf ball the bowling ball has more...?

Momentum, but less kinetic energy

From the same height you simultaneously drop a light weight tennis ball and a heavy weight bowling ball. When they hit the floor they have the same...?

Speed

A 50 kg sack is lifted 2 meters in the same time as a 25 kg stack is lifted 4 meters. The power expended in raising the 50 kg sack compared to the power used to lift the 25 kg stack is...?

The same

The distinction between impulse and force involves the...?

The time the force acts

If you do work on an object in half the time your power output is...?

Twice

If you push an object twice as far while applying the same force you do...?

Twice as much work

The most energy per unit mass can be extracted from...?

Uranium

Recoil is noticeable if we throw a heavy ball while standing on a skateboard. If instead we go through the throwing motion but hold onto the ball without friction our net recoil will be...?

Zero