Question

1. if you go from the earth to the moon which property changes - mass or weight? weight
2. what is the difference between mass and weight?
3. we use oils and lubricants in our machines to lessen __ and to increase __.
4. what are the six simple machines?
5. an axe is what kind of simple machine?
6. using a screwdriver to pry the top off of a can of paint is which kind of simple machine?
7. a ramp is an example of which type of simple machine?
8. what is an example of a wheel and axle?
9. what is the input force of a machine?

Explanation:

1. Mass is the amount of matter in an object (measured in kg), weight is the force of gravity on an object (measured in N). Weight depends on gravitational acceleration (\(W = mg\)), mass is constant.
2. Oils and lubricants reduce friction (lessen resistance between moving parts) and increase efficiency (machines work better with less energy loss).
3. The six simple machines are lever, wheel and axle, pulley, inclined plane, wedge, screw.
4. An axe is a wedge (used to separate objects, narrow end for splitting).
5. Using a screwdriver to pry is a lever (pivot point, effort arm and load arm).
6. A ramp is an inclined plane (allows moving objects up/down with less force over a longer distance).
7. Example of wheel and axle: doorknob (wheel - knob, axle - rod inside), car wheel (wheel rotates around axle).
8. Input force is the force applied to a machine (effort force, what you put in to make the machine work).

Answer:

1. Mass is the amount of matter; weight is gravitational force (\(W = mg\)).
2. Friction; efficiency.
3. Lever, wheel and axle, pulley, inclined plane, wedge, screw.
4. Wedge.
5. Lever.
6. Inclined plane.
7. Doorknob, car wheel.
8. Force applied to the machine (effort force).