2. By-Tanmaye Gupta ENERGY IGCSE PHYSICS

3. What is Energy? Energy is the capacity to do work. The S.I. unit of energy is Joules 1Joule = 10 7 erg http://ap-physics.david-s.org/

4. Other units of Energy. 1Wh = 3600J = 3.6 kJ Where W= watt k= kilo h= hour http://ap-physics.david-s.org/

5. Potential Energy The amount of energy stored in a body when it is stationary. P.E = mgh Where, m = mass (kg) g = gravity h = height http://ap-physics.david-s.org/

6. Kinetic Energy Kinetic energy is the energy possessed by a body when it is in motion. http://ap-physics.david-s.org/

7. Kinetic Energy Numericals 1. What is the kinetic energy of a jogger with a mass of 65.0 kg traveling at a speed of 2.5 m/s? Mass = 65.0 kg Velocity = 2.5m/s Kinetic Energy = 0.5*m*v 2 = 0.5*65*2.5 = 203.125 J http://ap-physics.david-s.org/

8. Potential Energy 1. Find the gravitational potential energy of a light that has a mass of 13.0 kg and is 4.8 m above the ground. Mass = 13.0kg Gravitational pull = 9.8 Height = 4.8 m Potential Energy = mgh = 13.0*9.8*4.8 = 611.52 J http://ap-physics.david-s.org/

9. Bibliography Physics World http://ap-physics.david-s.org/ THANKS FOR WATCHING http://ap-physics.david-s.org/