Question

Tarzan wants to use a vine to swing from the ground to a branch 5.0 m high in a nearby tree. If he runs at 8.0 m/s will he make it? If not, how fast must he run?

Answer 1

Answer:10 m/s

Explanation:

Given

Tarzan runs at v=8 m/s

Height of branch is h=5 m

Conserving Energy as it is constant at bottom point and on the branch

Energy at bottom is equal to kinetic Energy of Tarzan

$E_b=\frac{1}{2}mv^2$

Energy at top $E_{T}=mgh$

Equate

$m\cdot g\cdot h=\frac{1}{2}mv^2$

$v=\sqrt{2gh}$

$v=\sqrt{2\times 9.8\times 5}$

$v=9.89 \approx 10 m/s$

Thus velocity needed to reach branch is 10 m/s which is greater than 8 m/s so Tarzan will not make it to branch.

So he need to run at atleast 10 m/s