InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Here is an example with this lesson plan: Generally you can choose any level to e the reference level, but once chosen, be consistent. A 2.0 kg sloth hangs 5.0 m above the ground (Fig. 8-23). (a) What is the gravitational potential energy U of the sloth-Earth system if we take the reference point y=0 to be (1) at the grund, (2) at a balcony floor that is 3.0 m above the ground, (3) at the limb, and (4) 1.0 m above the limb? Take the gravitational potential energy to be zero at y=0. |
|
Answer» SOLUTION :KEY IDEA Once we have chosen the reference POINT for `y=0`, we can calculate the gravitational potential energy U of the system relative to that reference point with Eq. 8-50. Calculations: For choice (1), the sloth is at `y=5.0` m, and `U - mgy = (2.0 kg) (9.8 m//s^(2))(5.0 m) =98 J`. For the other choices, the values of U are (2) `U = mgy = MG (2.0 m) = 39J`. (3) `U = mgy = mg(0) = 0J`, (4) `U = mgy = mg(-1.0m)= - 19.6 J ~~ - 20J`. |
|