Experiment 16 Question(s)
Question:
I understand the kinetic energy part of the experiment but I don't understand the
potential energy part. Can you please help?
Answer:
You need to understand the following sequence of statements:
- The potential energy change of the cart is equal
to the work required to slowly raise the cart vertically, from its altitude at the low end
of the ramp to its altitude at the high end of the ramp.
- The force required to race the cart slowly is
equal and opposite to the weight of the cart.
- The work required to raise the cart is thus equal
to the weight of the cart multiplied by the altitude change.
- The weight of the cart is the force exerted on the
cart by gravity.
- Since we know that gravity accelerates freely
falling masses at 9.8 m/s^2, we know that the force exerted on a mass M by gravity is M *
9.8 m/s^2.
You should understand each of these statements, and you should understand the entire
argument.
- However, the bottom line for the experiment is
that the potential energy change is equal to the weight M g of the cart multiplied
by the altitude difference `dh between the and of the ramp.