A2L Item 164

Goal: Problem solving and developing strategic knowledge

Source: UMPERG-ctqpe102

You are given this problem:

A
block sits on an incline with friction. Given the height of the
block, the angle of incline, the coefficient of kinetic friction, and
that block starts from rest, find the speed at the bottom of the
incline.

What principle(s) would you use to solve the problem MOST EFFICIENTLY?

  1. Kinematics only
  2. F = ma or Newton’s laws
  3. Work-Energy theorem
  4. Impulse-Momentum theorem
  5. Angular Impulse-Angular Momentum
  6. 1 & 2
  7. 1 & 3
  8. 2 & 3
  9. none of the above
  10. Not enough information given

Commentary:

Answer

(3) The velocity can be determined using kinematics, but the 2nd
law is also needed, i.e. #6.