Question

17. A 15.0 kg water balloon is droppedfrom a balcony. If it strikes the ground with a speedof 20 m/s, how high is the balcony?

Answer 1

Given

m: mass

m = 15 kg

vo: initial speed

vo = 0m/s

vf: final speed

vf = 20 m/s

h: height

h = ?

Procedure

In the higher part the energy is potential of the system. In the lower part the energy is kinetic.

`\begin{gathered} U=K \\ \text{mgh}=(1)/(2)mv^2 \\ gh=(1)/(2)v^2 \\ h=(1)/(2)\cdot(v^2)/(g) \\ h=(20^2)/(2\cdot9.8) \\ h=20.40m \\ \end{gathered}`

The height would be 20.40 m