P 2 Physics Movement P 2 Physics Aims
- Slides: 8
P 2 - Physics Movement
P 2 – Physics - Aims � to discuss the transformation of kinetic energy to other forms of energy in particular situations
Movement When a body speeds up or slows down, its kinetic energy increases or decreases The forces which cause the change in speed do so by transferring energy to, or from, the body (object) When a force causes a body (object) to move through a distance, energy is transferred and work is done Work Done = Energy Transferred
Work Done, Force & Distance The amount of work done, force and distance are related by the equation: Work Done (joules, J) Force (newtons, N) Distance (metres, m) Moved in direction of force! W F × Work done against frictional forces is mainly transferred into heat D
Work Done, Force & Distance 1. Lucy pushes a book 5 m along the table with a force of 5 N. She gets tired and decides to call it a day. How much work did she do? 2. Vicci lifts a laptop 2 m into the air with a force of 10 N. How much work does she do? 3. Kern does 200 J of work by pushing a wheelbarrow with a force of 50 N. How far did he push it? 4. Chris cuddles his cat and lifts it 1. 5 m in the air. If he did 75 J of work how much force did he use? 5. Raymond drives his car 1000 m. If the engine was producing a driving force of 2000 N how much work did the car do?
Elastic Potential Energy For an object that is able to recover its original shape, elastic potential is the energy stored in the object when work is done on the object to change its shape
Kinetic Energy The kinetic energy of a body (object) depends on its mass and speed You can calculate the kinetic energy of a body using the equation:
Kinetic Energy 1) Siân drives her car at a speed of 30 m/s. If the combined mass of her and the car is 1000 kg what is her kinetic energy? 2) Kim rides her bike at a speed of 10 m/s. If the combined mass of Kim and her bike is 80 kg what is her kinetic energy? 3) Tommy is running and has a kinetic energy of 750 J. If his mass is 60 kg how fast is he running? 4) Katherine is walking to town. If she has a kinetic energy of 150 J and she’s walking at a pace of 2 m/s what is her mass?