Question

At the top of a giant swing on the gymnastics high bar, candy's velocity is 1 m/s, and she is 3.5 m high. if candy's mass is 50 kg, what is her total mechanical energy at this instant?

Answer 1

The total mechanical energy is the sum of the kinetic energy and the gravitational potential energy:
$E=K+U= \frac{1}{2}mv^2 +mgh$
where m=3.5 kg is Candy's mass, v=1 m/s is her velocity and h=3.5 m is her height. If we replace these numbers, we find the mechanical energy of the system:
$E= \frac{1}{2} (50 kg)(1m/s)^2 + (50 kg)(9.81 m/s^2)(3.5 m)=1742 J =1.74 kJ$