Work done and energy transfers Flashcards
1
Q
What does it mean if a force is said to do ‘work’?
A
The force causes an object to be displaced through a distance.
2
Q
What is the equation used to calculate work done? Give appropriate units
A
Work done = force x distance Work done (joules), force (newtons), distance (meters).
3
Q
What distance must be used when calculating work done?
A
It must be the distance that is moved along the line of action of the force.
4
Q
Under what circumstances is 1 joule of work done?
A
When a force of 1N causes a displacement of 1m.
5
Q
How many newton-meters are equal to 1 joule of energy?
A
1 Nm = 1 J
6
Q
What occurs when work is done against frictional forces?
A
- A rise in temperature of the object occurs.
- Kinetic energy is converted/wasted as heat and dissipated to surroundings.
7
Q
Why does air resistance slow down a projectile?
A
- The object does work against the air resistance.
- Kinetic energy is converted in to heat, slowing down the object.
