Skip to main content

Back to the full dot-point answer

SingaporePhysicsQuick questions

Newtonian Mechanics

Quick questions on Work, energy and power explained: H2 Physics Newtonian Mechanics

6short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is work done by a force?
Show answer
Work is done when a force moves its point of application. For a constant force FF and displacement ss at angle θ\theta between them:
What is the work-energy theorem?
Show answer
The net work done on a body equals its change in kinetic energy:
What is conservation of energy?
Show answer
Energy cannot be created or destroyed, only transferred. For a system with only conservative forces (gravity), mechanical energy is conserved:
What is q1?
Show answer
Define work done by a force and state the condition under which a force does no work. [2 marks]
What is q2?
Show answer
A 0.20 kg0.20\ \text{kg} ball is dropped from 2.0 m2.0\ \text{m}. Using energy conservation, find its speed just before hitting the ground (ignore air resistance). [2 marks]
What is q3?
Show answer
A motor lifts a 50 kg50\ \text{kg} load at constant speed 0.40 m s10.40\ \text{m s}^{-1}. The motor draws 300 W300\ \text{W}. Find its efficiency.

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All PhysicsQ&A pages