Question

Use the following picture to answer questions #6 and 7. Consider that after the snowboarder starts down from the hill from point A, she travels all the way to the end of the path.

6. Standing still at the top of the hill at point A, what kind of energy (potential and/or kinetic) would the snowboarder have? How do you know?

7. Explain the energy conversion from point C to point B. Make sure to include a description of both kinetic and potential energy.

Answer 1

Remeber:

Kinectic energy = [1/2]mv^2
Potential energy = m.g[h - h0]

6. When the snowboarder is still at the top, she does not have kinetic energy, given that the speed is zero.

There, at the top, the potential energy is maximum, given that the height, h - h0, is the highest.

So, ar the topo she only has potential energy.

7. From that point, the snowboarder, starts to gain velocity; is has started a process of conversion of potential energy to kinetic energy. More velocity, less height, more kinetic ener energy and less ptential energy.

At the very bottom, when she has reached the heigth of reference, h0, the term [h - h0] becomes zero, then the potential energy has dissapeared and all the energy has been transformed into kinetic energy; the speed and the kinetic energy are maximum.