Why is the answer b? i'm not sure which equation to look at when doing these proportion types of problems.

Explanation:

Given:

Δy = d

v₀ = 0

a = g

Find: v

v² = v₀² + 2aΔy

v² = (0)² + 2(g)(d)

v = √(2gd)

If we double d:

√(2g (2d))

√(4gd)

Compared to the first velocity:

√(4gd) / √(2gd)

√2

So the new velocity is √2 greater than the first velocity.

√2 v

explanation:

the answer is b, have negligible mass