Work and energy

Question 1

What is work

Answer 1

Work is done when a force acts on a moving body. Work is done whenever a force moves something.

Question 2

What does the kinetic energy of an object depend on

Answer 2

Mass and speed

Question 3

What is elastic potential

Answer 3

A force acting on an object may cause the shape of an object to change. Elastic objects can store elastic potential energy if they are stretched. For example, this happens when a catapult is used.

Question 4

What is Hooke’s law

Answer 4

When an elastic object, such as a spring, is stretched, the increased length is called its extension. The extension of an elastic object is directly proportional to the force applied to it:

Question 5

Why do cars have safety features

Answer 5

Modern cars have safety features that absorb kinetic energy in collisions.

Question 6

What is a crumple zone

Answer 6

Crumple zones are areas of a vehicle that are designed to crush in a controlled way in a collision. They increase the time taken to change the momentum of the driver and passengers in a crash, which reduces the force involved.