Do two negatives equal a positive

A water rocket has a mass of 0.8kg and is launched in a school playground with an inital upwards force of 12newtons.

If the pitch of a sound decreases and the sound source is moving, is the sound source moving toward or away from the observer?

Net force needed to accelerate a 1000-kg car at 0.5g

How would you describe the elevation and relief of a plain

What is newton's disc? How does it show that light is composed of many colours?

Determine the total mechanical energy of a 250 g baseball if it has a velocity of 30 m/s when it leaves the pitcher's hand 1.2m above the ground.

When distances were carefully measured from Earth to globular clusters above and below the Milky Way plane (where our view of them is not obscured by interstellar dust and gas), their distribution was found to be

Imagine you transfer heat into a gas. This heat splits up in two different ways: Additional thermal energy making the gas hotter and "fuel" for the gas to do work. Let's suppose, 64% of the transferred heat transforms into thermal energy.

How much heat is absorbed by a 61g iron skillet when its temperature rises from 5oC to 29oC?

Explain the relationship between motion and frame of reference.