Unit 2.3 - Work and Energy

Question 1

Describe the effect of a force acting on a moving body on the energy involved.

Answer 1

Energy is transferred although the total amount of energy remains constant.

Question 2

What is work a measure of (in the absence of a thermal transfer)?

Answer 2

Energy transferred.

Question 3

What three things result in an object possessing energy?

Answer 3

Its motion (kinetic energy), position (gravitational potential energy) and deformation (elastic energy).

Question 4

What is the relationship between force and extension for a spring or simple system and how is this represented on a graph?

Answer 4

Force = extension * spring constant (on a graph, spring constant is the gradient).

Question 5

What does the area under a Force-extension graph represent?

Answer 5

Area under graph = Work Done

Question 6

What four ways can the efficiency of vehicles be improved? Give an example of each of these.

Answer 6

Reducing aerodynamic losses/air resistance (more aerodynamic shape), reducing rolling resistance (high tire pressure), idling losses (automatic stop-start system), and inertial losses (build cars from lightweight materials).