ENERGY TEST
Energy is the ability to ____.
A) do work B)create power C)heat something
To do work, something must ____.
A)work B)move C)go up
The unit used to measure energy is the ___.
A)Newton B)Joule C)Kg
Kinetic energy is the energy that ____ objects have.
A)high up B)hot C)moving D)potential
If you double mass, KE will ____.
A)stay the same B)double C)quadruple
If you double velocity, KE will ____.
A)stay the same B)double C)quadruple
If you want to find the KE of an object you must know what?
A)its velocity B)its height C)its PE
KE is measured in what unit?
A)Newton B)Joule C)Kg
Potential energy is energy that comes from…
A)motion B)position C)power D)velocity
Since most of our problems involve things here on Earth, for “g” we use ____.
A)1.6m/s/s B)9.8m/s/s C)9.8J D)2.2Kg
Since W=F*d and F=ma, then we can see that W=____.
A)ma/d B)d/ma C)mad D)none of these
At ground level, a 10Kg rock that had fallen from 10m up would have a PE of ____J.
A)zero B)about 1000J C)about 10J
A cannonball loses ___ and gains ___as it reaches the top of its flight.
A)PE,KE B)KE,PE C)KE,KE D)PE,PE
A ball will never bounce up to the height you dropped it from because energy is…
A)lost B)converted
Friction typically reduces machine efficiency by radiating ____.
A)light B)sound C)heat D)electrical
Light and heat are types of energy that travel as waves. They are referred to as ____ energy.
A)radiant B)kinetic C)potential D)chemical E)electrical
One type of energy that we didn’t talk about in class comes from the center of atoms. This is ____.
A)chemical B)radiant C)nuclear
One type of potential energy we use every day travels through wires to get here. It is ____.
A)radiant B)kinetic C)potential D)chemical E)electrical
The amount of work done per unit of time is the ___ of something.
A)energy B)work C)force D)power E)none of these
It is possible to do the same job twice, but with a different power each time.
A)True B)False
The unit we pay for our electricity is the ____.
A)Kw B)J C)KwH D)watt/sec
One watt = one ____.
A)J/s B)N/m C)Kw
If you cut the time it takes to do a job in half, what have you done to your power?
A)same B)double C)quadruple
Energy can be created and destroyed
A)True B)False
PROBLEMS:
If you leave a 1000watt electric stove on for 3 hours and one KwH is 10 cents, how much do you have to pay?
A 1000Kg car moving 5m/s has how much KE?
An 85Kg Mock 6m up a tree has how much PE?
If you use 400J in 35sec, how many watts were developed?
Essay choices:
A)Someone asks you, “Why do I need to know about energy being converted from one type to another?” What do you say to them?
B)Describe PE & KE as a kid goes back and forth on a swing
C)What are some energy changes that take place as you drive a car?