Need help on Physics equations.?

1) y = ½at²
y = displacement from rest
a = acceleration
t = time elapsed from rest
Plug in the two values you have and solve for the third.

2) x = Vo*t + ½at²
Same as above, except now instead of starting from rest, the object starts with some initial velocity Vo. Plug in the three values you have and solve for the fourth.

3) v = √(2ax)
v = velocity
after accelerating from rest at rate "a"
for a distance of "x".
Plug in the two values you have and solve for the third.
For instance, if you have v and a, then x = v² / 2a

4) Looks like Newton's Law of Gravitation, except that usually we use "G" and not "k":
F = G * m1 * m2 / r²
where G is Newton's constant
and m1 and m2 are the two masses
and r is the distance between their centers
and F is the resulting gravitational force.
Plug in the three knowns and G (or k if you prefer) and solve for the fourth.

If you find this helpful, please award Best Answer!