Difference between revisions of "Work Done"
| Line 15: | Line 15: | ||
===Example Calculations=== | ===Example Calculations=== | ||
: 1. A person lifts a 40N box by a height of 1.2m. Calculate the work done by the person against gravity. | : 1. A person lifts a 40N box by a height of 1.2m. Calculate the work done by the person against gravity. | ||
| − | Force = 40N | + | : Force = 40N |
| − | Distance moved in the direction of the force = 1.2m | + | : Distance moved in the direction of the force = 1.2m |
:<math> W = Fd</math> | :<math> W = Fd</math> | ||
:<math> W = 40 \times 1.2</math> | :<math> W = 40 \times 1.2</math> | ||
Revision as of 10:16, 9 October 2018
Key Stage 3
Meaning
Work Done is the amount of energy transferred by the action of a force.
About Work Done
- Work Done is measured in Joules.
- Work Done can only be calculated for objects moving in the direction of the force.
Equation
\[ Work Done = Force \times Distance moved in the direction of the force\] \[ W = F \times d\] \[ W = Fd\]
- Work done is written with a capital W. Force is written with a capital F. Distance is written with a lower case d.
Example Calculations
- 1. A person lifts a 40N box by a height of 1.2m. Calculate the work done by the person against gravity.
- Force = 40N
- Distance moved in the direction of the force = 1.2m
\[ W = Fd\] \[ W = 40 \times 1.2\] \[ W = 48J\]
- 2. The brakes on a car apply a force of 10,000N. The car travels a distance of 15m braking. Calculate the work done by the brakes.
- 3. A person carries a 20N box along a horizontal path of 20m.