Work and Power Basics
This is the amount of force applied over a certain distance or Blank = Force x distance
Work
A man that weighs 600N is standing on a desk that is 0.5m tall. How much work is he doing?
0
Name 3 types of simple machines
Lever, Inclined Plane, Wheel and Axle (also: Pully, wedge, screw)
I apply a force 30cm away from the fulcrum and it lifts a weight that is 50cm away from the fulcrum. What is the lever's IMA?
0.6
This the rate at which work is done or Blank = Work/time
Power
If you perform 40 joules of work lifting a 10-N box from the floor to a shelf, how high is the shelf?
4m
Give a real life example of a lever
Seesaw, wheelbarrow, shovel, lightswitch
A 10cm radius wheel is attached to a 5cm radius axel. What is the IMA?
2
These are the units for Work and Power (which is which?)
Work - Joules (J) or N*m
Power - Watts (W)
If I do 500J of work traveling up a flight of stairs and it takes me 20 seconds to do it, how much power do I have?
25W
What is required to get work out of a machine?
How do I increase the Mechanical Advantage of a lever?
By moving the fulcrum closer to the load.
How much time is needed to produce 720 Joules of work if 90 watts of power is used?
3 seconds
A ramp that is 36ft long and 12 ft high has what IMA
3
I have 2 different ramps. Both of them have a length of 100cm. One of them is 10cm high and one is 50cm high. Which ramp is more advantageous to use?
The 10cm ramp.
A crane can lift 5,000N of materials 300m into the air in 60 seconds. What is the crane's power?
25,000W
Ramps make work easier by...
Increasing the distance over which force is applied
If I exert 25lbs of effort of a lever with MA = 5, how heavy of a load can I lift?
125lbs