I think the correct answer is A mark has greater gravitational potential energy
:)
Oil as you might notice is used in moving parts in machines.
The reason being is that oil is a smooth type of liquid.
So when machine parts are moving with oil on them, the oil allows the machine parts to move more smoothly. So when there is a squeaky noise on a moving part on a machine, mechanics/workers often put oil to make it more smooth because the moving parts are rubbing off on each other.
Answer:
35 kilogram per stair will weight
4 looks ok
The direction of travel. Q asks for a velocity. Velocity is a vector. Vectors have magnitude and direction.
Olive oil, because it's a liquid? The rest are solids.