4.) An apartment building is on fire and a guy is trapped on the fire escape ladder. There is a

dumpster that is 6.3m away and is filled full of trash, and he is 7m above it. If he jumps totally

in the horizontal direction, how fast does he have to jump in order to land in the dumpster?

5.3 m/s

Explanation:

First, find the time it takes for him to fall 7m.

y = y₀ + v₀ t + ½ at²

0 = 7 + (0) t + ½ (-9.8) t²

0 = 7 - 4.9 t²

t ≈ 1.20 s

Now find the velocity he needs to travel 6.3m in that time.

x = x₀ + v₀ t + ½ at²

6.3 = 0 + v₀ (1.20) + ½ (0) (1.20) ²

v₀ ≈ 5.27 m/s

Rounded to two significant figures, the man must run with a speed of 5.3 m/s.