Types of Energy
The ability to do work.
What is energy?
The following is an example of electromagnetic energy? a) a speeding car b)sunlight c) a falling stone d) a stretched bowstring
What is b) sunlight?
Work is a) the product of speed and force b) the sum of power and force c)the product of force and distance d) the sum of motion and force
What is c) the product of force and distance (W=Fxd)
A screw can be considered this type of simple machine: a) lever b) inclined plane c) pulley d) wedge
What is b) inclined plane (wrapped around a central axis)
A small meteoroid is approaching Earth. It has a mass of 120.0 kg and a speed of 20.0 km/s. How much kinetic energy does the meteoroid have? (Hint 1 km = 1000 m) KE= 1/2 x m x v2
What is 24,000 J?
Energy that is stored as a result of position or shape
What is potential energy?
What is c) chemical energy?
The following is a unit of work: a) joule b) watt c) horsepower d)newton
What is a) joule? (a unit of work and energy)
When the output force of a machine with a mechanical advantage is much larger than 1, this is true
a) the output force is much less than its input force
b) the output force is much larger than its input force
c) work output is about the same as work input
d) work output is always zero
What is b) the output force is much larger than its input force?
Suppose a 200.0 kg building supplies are lifted in the air to be placed onto a workstation. This much energy is needed to lift the supplies 3 meters into the air. (PE = mxgxh)
What is 5880 J?
What is kinetic energy?
Friction causes kinetic energy to be converted into a) potential energy b) mechanical energy c) chemical energy d)thermal energy
What is d) thermal energy?
Power is equal to work divided by the following variable: a) time b) force c) distance d) mechanical advantage
What is a) time?
What is friction? IMA is the advantage if there were no friction to overcome.
You exert a force of 500 N to walk 4 m up a flight of stairs in 4 s. You used this much power.
What is 500 W? P=w/t = Fxd/t
The following is an example of an object with elastic potential energy: a? a stretched spring b) a moving arrow c) books on a shelf d) a falling oyster
What is a) a stretched spring?
This is a process that releases energy by splitting atomic nuclei apart.
What is nuclear fission?
Work output of a machine is related to its input in this way:
a) work output is always less than work input
b) work output is always greater than work input
c) work output is about the same as work input
d) work output is always zero
What is a) work output is always less than work input (due to friction)?
The percentage of work input that becomes work output is called this.
What is efficiency?
Say you are cracking nuts with a nutcracker. You apply an input force of 12.5 N to the nutcracker while the output force is 50 N. The actual mechanical advantage of the nutcracker is this. (AMA = output force/input force)
What is 4?
If the speed of an object doubles, this happens to its kinetic energy. a) KE doubles b) KE stays the same c) KE is halved d) KE quadruples
What is d) KE quadruples? (KE is directly proportional to the square of the speed)
The law of conservation of energy says this.
What is "Energy cannot be created or destroyed; it can only be converted from one form to another or transferred from one object to another."?
The amount of work done each second is called this.
What is power? P=W/T
The six types of simples machines listed in our text were these.
If you exert 95 N of force on a jack to lift a 9,500 N car, this would be the jack's actual mechanical advantage. (AMA = Output Force/Input Force)
What is 100?