What type of simple machine is found in our bodies and give an example.
lever
Example: neck, ankle,elbow
100
What is a machine that uses 2 or more simple machines?
a compound machine
100
A figure skater lifts his partner , who weighs 400 N, 2 m in 5 sec. How much power is required?
160 W
100
lever
a bar that is free to pivot , or turn, about a fixed point
200
What 2 forces are used to do work?
effort force and resistance force
200
How many classes of levers are there?
3
200
What is a measure of how much of the work put into a machine is changed to useful work out out by a machine?
efficiency
200
A worker applies an effort force of 25 N to pry open a window that has a resistance force of 300N. What is the mechanical advantage of the crowbar?
12
200
a device that does work with only one movement
simple machine
300
What do you call a machine in which work input equals work output?
ideal machine
300
In a wheel and axle, what is the effort force usually applied to ?
larger wheel
300
How is efficiency expressed?
as a percentage
300
A carpenter uses a claw hammer to pull a nail from a board. The nail has a resistance of 2500 N. The carpenter applies an effort force of 125 N. What is the mechanical advantage of the hammer?
20
300
the fixed point of a lever
fulcrum
400
How do you calculate Mechanical Advantage?
resistance force by effort force
400
Give an example of a wedge.
chisel blade, ax blades, or knife blades
400
How do you calculate power?
Work over time
400
The IMA of an inclined plane 8 m long and 2 m high is_
2, 4, 8, or 16
4
400
Power
The rate at which work is done
500
What is the mechanical advantage when the effort force and resistance force are equal?
1
500
Name all 6 simple machines
lever, wheel and axle, wedge, pulley, screw, inclined plane
500
Which of these can not be done by a machine?
multiply force
multiply energy
change direction of a force
work
multiply energy
500
A worker uses an iron bar to raise a manhole cover weighing 65 N. The effort arm of a lever is 45 cm long. The resistance arm is 15 cm long. What is the ideal mechanical advantage?
3.0
500
What is the measure of how much of the work put into a machine is changed to useful work put out by a machine.