A2L Item 165
- Description: Identify the correct principle to solve the problem most efficiently.
- Goal: Problem solving and developing strategic knowledge
- Source: UMPERG-ctqpe103
- Keywords: Energy, Mechanics, Problem Solving, Strategic Approach, Velocity
The question for students:
You are given this problem:
{: .image-right } A block sits on a frictionless incline. Given the angle of incline, the distance along the incline, and that the block is initially at rest, find the speed after traveling a distance d.
What principle would you use to solve the problem MOST EFFICIENTLY?
- Kinematics only
- F = ma or Newton’s laws
- Work-Energy theorem
- Impulse-Momentum theorem
- Angular Impulse-Angular Momentum
- 1 and 2
- 1 and 3
- 2 and 3
- None of the above
- Not enough information given
Commentary for teachers:
Answer
(3) The change in gravitational potential can be found directly. Alternately, the work done by the gravitational force must be equal to the change in kinetic energy.