Question

Can anyone help me with this last question?

Answer 1

v = 39.6 m/s (first answer option)

Step-by-step explanation:

Use conservation of mechanical energy.

The starting is completely potential energy and the final is all kinetic energy:

`m*g*h=(1)/(2)*m*v^2\\g * h=(1)/(2) v^2\\9.8*80=(1)/(2) v^2\\v^2=1568\\v\approx 39.6\,\,m/s`

which agrees with the first answer shown.