Vocab
This is the transfer of energy when a force moves an object.
Work
A student pushes a wall but the wall does not move.
No work.
Jaina's cat Icarus has a mass of 10 kg. How much does Icarus weigh, in Newtons?
98 N
A doorknob is this type of machine.
wheel and axle
A machine multiplies your force 3 times.
What is its mechanical advantage?
3
A push or pull
Force
A student pushes a desk across the classroom floor.
Yes! Work is done!
A student pushes a box with 10 N of force for 5 m.
What is the work done?
50 J
A knife used to split wood is this type of machine.
Wedge
Input force = 10 N
Output force = 50 N
Mechanical advantage = ?
5
The unit measuring energy, including as the unit for work
Joules
A student walks up stairs carrying a heavy back pack.
Yes. Work is done!
A construction worker uses a 12 meter ramp to lift a 3 N object 4 meters off the ground. What is the work output?
12 N
A flagpole that uses a rope to raise a flag uses this machine.
pulley
If a lever is set up to have a resistance arm of 12 cm and an effort arm of 36 cm, what is the mechanical advantage?
3
The point on a lever where it pivots.
Fulcrum
A student carries a heavy backpack across the hallway.
no work.
A worker does 200 J of work while moving a box 10 m. How much force was applied?
20 N
A jar lid or a spiral staircase is an example of this machine.
screw
If the mechanical advantage of a ramp is 3, how high off the ground was an object lifted after traveling along the ramp for 12 meters?
4 meters off the ground
This term describes how much a machine multiplies force.
mechanical advantage
A builder uses a crowbar to remove a nail.
Yes.
A 150 kg object lifted 4 m requires how much work? Please assume gravity is 10 m/s2?
6000 J
Which type of machine is often used to change the direction of the force, but not the amount of force needed?
pulley
A pulley system requires 4N of force to pull back curtains weighing 20 N. How many wheels is this pulley system composed of?
5 wheels