Question

A water balloon is dropped out of a fifth floor window and hits an unsuspecting person below 4.0 seconds later. The window is approximately

80 m high

10 m high

40 m high

160 m high

4 m high

Answer 1

80 meters high

Step-by-step explanation:

The velocity of the balloon would be g*t (I won't calculate, but will us this later)

We know that the kinetic energy at the bottom equals the potential at the top.

KE = PE

1/2 * m * v^2 = m * g * h

1/2 * m * (g * t)^2 = m * g * h (substitution)

1/2 * m * g^2 * t^2 = m * g * h

1/2 * g * t^2 = h (simplification by dividing the commons between both sides)

h = 1/2 * 9.81 * 4^2

h = 78.48 m (roughly 80 m)