Laws of Motion and Energy

Chapter Six: Energy and Machines 6.1 Energy and Conservation of Energy 6.2 Work and Power 6.3 Simple Machines

6.2 Work In science, work is a form of energy that comes from force applied over distance. A force of 1 newton applied for 1 meter does 1 joule of work on the block.

6.2 Work and Energy Doing work always means transferring energy. The work you do stretching the rubber band is stored as energy in the rubber band. The rubber band can then use the energy to do work on a paper airplane. potential energy Converted to kinetic energy

6.2 Work and energy Sometimes force is applied to an object, but no work is done. If you push on a block and it doesn’t move, you have not done ANY work in the scientific sense. Which force is most likely to do work on the block?

6.2 Calculating work in joules To calculate work, you multiply the force by the distance the object moves in the direction of the force. How much work is done if the block is raised 3 meters?

6.3 Calculating work in joules Work is done by forces over a distance. Work is done on objects.

6.3 Power Power is the rate at which work is done. Michael and Jim each do the same work. Who has the most POWER?

6.3 Calculating power Michael’s power is his work (200 joules) divided by his time (1 second). Michael has a power of 200 watts. Jim’s power is only 20 watts because he takes 10 times longer to lift the weights.