Presentation on theme: "Energy Conversion of Energy Forms of Energy Energy Work."— Presentation transcript:
Energy Conversion of Energy Forms of Energy Energy Work
Work The product of force and distance moved in the direction of the force W = F x d Units: Newton-meter, Nm –Equivalent to Joule, J
Work Example A force of 10N is applied to a box to move it 2m along the floor. What is the work done on the box? A bodybuilder, 1.6 m tall lifted a 30-kg mass from the ground up to his head. How much work did he do?
Example 1 A box of mass of mass 3 kg is dropped from a height of 5m. Neglecting air resistance, calculate: –The potential energy of the box before it is dropped –The kinetic energy of the box just before it reaches the ground –The speed of the box just before it strikes the ground
Example 2 A ball of mass 60 g is thrown upwards with an initial speed of 30 m/s. If air resistance is negligible, calculate: –The initial kinetic energy of the ball –The initial potential energy of the ball –The potential energy of the ball when it reaches its greatest height –The greatest height reached by the ball