Question

Tarzan (75 kg) swings from 4 metres high on a vine down to ground level and catches Jane (50 kg). How fast are they moving after he cares her?

Answer 1

Try this solution (if it is possible, check it in other sources):

1. for m_Tarzan=75kg., initial_height=4m., end_height=0 m. and g=10 N/kg. Energy is:

`E=m_(Tarzan)*(H_(initial)-H_(end))*g=75*4*10=3000(J).`

2. The same value of Energy is applied for m_Tarzan+Jane=75+50=125 kg.:

`E=(m_(Tarzan+Jane)* Speed^2)/(2); \ => \ Speed=\sqrt{ (2*E)/(m_(Tarzan+Jane))};`

3. According to the formula of the Speed:

Speed=sqrt(6000/125)=sqrt(48)=4sqrt(3)≈4*1.71=6.84 (m/s)

Answer: 6.84 (m. per sec.)