In physics, work is defined as:
force applied over a distance
If a machine does 100 Joules of work in 5 seconds, what is its power output?
20 W
A pulley system lifts a 200 N load when you apply 50 N of pulling force. What is the mechanical advantage?
4
An axe used to split wood is an example of which simple machine?
wedge
What is the standard SI unit for work?
Joule
The primary purpose of a machine is to:
make work easier
The efficiency of a machine is a measure of:
how much of the work input becomes useful work output
A seesaw on a playground is an example of which simple machine?
lever
Power is defined as:
the rate at which work is done
If a simple machine reduces the amount of force you need to apply, what must you trade in return?
You must apply the force over a longer distance.
Why is the efficiency of a real machine always less than 100%?
Some energy is converted to heat by friction.
What does a single fixed pulley change about the input force?
a) The amount of work required
b) The total amount of energy
c) Only the magnitude (size) of the force
d) Only the direction of the force
Only the direction of the force
What is the standard SI unit for power?
Watt
The force applied to a machine by the user is called the:
Input force
A student carries a heavy 100 N box horizontally across the room for 5 meters at a constant speed. How much scientific work was done on the box during the walk?
0 J
What is the difference between Ideal Mechanical Advantage (IMA) and Actual Mechanical Advantage (AMA)?
a) AMA ignores friction; IMA includes the effects of friction
b) IMA ignores friction; AMA includes the effects of friction
c) IMA is always smaller than AMA
d) There is no difference
IMA ignores friction; AMA includes the effects of friction
If you apply 50 N of force to push a box 2 meters, how much work have you done?
100 J
Mechanical Advantage (MA) is defined as the ratio of:
output force to input force
A ramp used to load boxes onto a truck is an example of which simple machine?
Inclined plane
A bicycle consists of levers, pulleys, and wheel and axles working together. What is this called?
Compound machine