Answer:
A force
Explanation:
A push or a pull is an example of a force and can cause an object to speed up, slow down, etc.. Newton's laws tell us that 1- an object will not change its motion unless a force acts on it 2- the force on an object is equal to its mass times its acceleration. 3- The third law states that for every action (force) in nature there is an equal and opposite reaction.. However, forces like gravity and friction can resist movement.
Well, you gave us the formula to calculate power from work and time,
but you didn't give us the formula for work. We have to know that.
Work = (force) x (distance)
The work to raise Sara to the top of the hill is
Work = (300 N) x (15 meters)
= 4,500 newton-meters = 4,500 joules .
Now we're ready to use the formula that you gave us. (Thank you.)
Power = (work) / (time)
= (4,500 joules) / (10 seconds)
450 joules/second = 450 watts.
The answer might be B because the value is negative, and negative could mean slowing down.
Mechanics is dealing with forces that are effecting some body, electrostatics is about electrical fields of not moving bodies, and quantum mechanics is dealing with quantum states of atoms.
Thermodynamics as the word say, is dealing with thermal energy that is moving (transferring from one body to another or even better from one medium to another).
Answer is C <span />