Question

If a force acts on an object only to accelerate it what is true about the equations: w=Fs and Ek =1/2mv^2-1/2mu^2

Answer 1

$$W=Fs$$

is true only if F is the constant force.

$$\Delta E_k =\frac{1}{2}mv^2-\frac{1}{2}mu^2$$

is the formula for the change in the kinetic energy.

We have:

$$\Delta E_k =W$$

$$\frac{1}{2}mv^2-\frac{1}{2}mu^2=Fs$$