P5- Work Done And Energy Transfers ((5.2)) 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 (Joules) = Force x Distance
W=fd
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 circumstance is 1 joule of work done?
A
When a force of 1 Newton cause a displacement of 1 metre
5
Q
How many Newton-metres are equal to 1 joule of energy?
A
1Nm= 1J
6
Q
What occurs when work is done against frictional forces?
A
- a rise in temperature of the object occurs
- kinetic energy is converted to heat
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
