A2L Item 163

Goal: Problem solving and developing strategic knowledge

Source: UMPERG-ctqpe101

You are given this problem:

A
block sits on a frictionless incline. Given the angle of incline, the
distance along incline, and the mass of block, find the acceleration
after traveling a distance d.

What principle 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-Ang. Momentum
  6. More than one of the above
  7. Not enough information given

Commentary:

Answer

(2) The 2nd law is needed to find the acceleration. Students who
answer that only kinematics is needed are relying on memory.