Question

Are my answers correct?

Answer 1

Explanation:

Your answers to 1 and 4 are correct, and your answer to 5 is half correct.

2. d = ((vf + vi) / 2) t

To solve for t, divide both sides by what's in the parenthesis:

d / ((vf + vi) / 2) = t

If you wish, you can simplify:

t = 2d / (vf + vi)

3. d = vi t + ½ a t²

To solve for a, first subtract vi t from both sides:

d − vi t = ½ a t²

Multiply both sides by 2:

2d − 2 vi t = a t²

Divide by t²:

a = (2d − 2 vi t) / t²

To solve for t when vi = 0, first substitute 0 for vi:

d = (0) t + ½ a t²

d = ½ a t²

Multiply both sides by 2:

2d = a t²

Divide both sides by a:

t² = 2d / a

Take the square root:

t = √(2d / a)

5. Fg = G m₁ m₂ / r²

To solve for r, first multiply both sides by r²:

Fg r² = G m₁ m₂

Divide both sides by Fg:

r² = G m₁ m₂ / Fg

Take the square root;

r = √(G m₁ m₂ / Fg)

Your other answer is correct.

Overall, good effort!