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Formative assessment questions for teaching physics

A2L Item 163

  • Description: Identify the correct principle to solve the problem most efficiently.
  • Goal: Problem solving and developing strategic knowledge
  • Source: UMPERG-ctqpe101
  • Keywords: Acceleration, Dynamics, Mechanics, Problem Solving, Strategic Approach

The question for students:

You are given this problem:

![Item163_fig1.gif](../images/Item163_fig1.gif){: .image-right } 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 for teachers:

Answer

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