Solution Found!
Answer: A crate of mass M starts from rest at the top of a
Chapter 7, Problem 6E(choose chapter or problem)
Problem 6E
A crate of mass M starts from rest at the top of a frictionless ramp inclined at an angle α above the horizontal. Find its speed at the bottom of the ramp, a distance d from where it started. Do this in two ways: Take the level at which the potential energy is zero to be (a) at the bottom of the ramp with y positive upward, and (b) at the top of the ramp with y positive upward. (c) Why didn’t the normal force enter into your solution?
Questions & Answers
QUESTION:
Problem 6E
A crate of mass M starts from rest at the top of a frictionless ramp inclined at an angle α above the horizontal. Find its speed at the bottom of the ramp, a distance d from where it started. Do this in two ways: Take the level at which the potential energy is zero to be (a) at the bottom of the ramp with y positive upward, and (b) at the top of the ramp with y positive upward. (c) Why didn’t the normal force enter into your solution?
ANSWER:
Solution 6E
a)
Mass of the crate is M.
The angle is .
The distance is d.
Height of the ramp we can get by a little use of trigonometry.
.
The potential energy at the top was “Mgh”.
The potential energy at the bottom was zero.
Kinetic energy at the top was zero and at the bottom was .
By the conservation of mechanical energy,