1. if the work done to move a box to a distance of 6 metres equals 120 joules. calculate the force 2. Calculate the potential energy of a book with a mass of 1.5 kg placed on top of a shelf with a height of 2 m.
(Knowing that the acceleration due to gravity = 10 m/s2
).

3. What is meant by?
The potential energy of an object = 20 joules.

An experiment is designed to test the relationship between the initial height of a basketball before it is dropped to the height of its rebound bounce. the height of the rebound bounce is measured using a scale positioned behind the ball. in the above experiment, which condition would not be controlled? a). the starting height of the ballb). the surface the ball bounces on c). the type of ball d). the method to measure the rebound height of the ball

Suppose you have three polarizing filters, with the second at an angle of 42∘ to the first and the third at an angle of 90∘ to the first. by what perfect will the original intensity of unpolarized light be reduced to after passing through all three filters?

Describe uniform velocity and variable velocity in short