5. A ball is thrown vertically upward from an initial position 5m above the ground. At the same time, a cube is released from rest down a slippery incline, from an unknown height. The two objects reach the ground at the same instant, and both have a final speed of 15m/s. What is the angle of the incline

see earlier answer

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.

the components of a vector are the parts of the vectors that are to each other.

b perpendicular

f=ma newton's second law 7x8=56n