<em>velocity over time I think</em>
Answer:

Explanation:
Potential Energy= Kinetic Energy
Let
be the value of Kinetic Energy.
We know that

Make
the subject of the formula to get speed at the bottom of the hill.

It is (A) for the first one and (B) for the second one.
Answer:
390 J
Explanation:
m = 3 kg
u = 16 i + 2 j
(a) Magnitude of velocity =
= 16.1245 m/s
KEi = 1/2 m v^2 = 0.5 x 3 x 16.1245 = 390 J
(b) v = 18 i + 14 j
Magnitude of velocity =
= 22.804 m/s
KEf = 1/2 m v^2 = 0.5 x 3 x 22.804 = 780 J
According to the work energy theorem
Work done = change in KE = KEf - KEi = 780 - 390 = 390 J