Work & Power How the world works.... Work or Not? 11-0 What is Energy? • Energy - ability to cause change: can change the speed, direction, shape, or temperature of an objoct Define / Describe WORK • Work is done when a force causes an object to move in the direction that the force is applied. • The formula for work is: W = F X D • It there is no movement, there is no work Joules? Work is measured in Joules Nior york Work (Joules) - Force (Newtons) X meters)| Exampie to calculate Work Question: A weightifter raises weights of 2000 weight of 2 meters. How much work has been done W - 2000 X 2 W = 4000 Joules What is Power? Power is the rate at which work is done. Power is measured in Watts. Power (Watts) = Work (Joules) / Time P-W/? Question: A weightifter ifted 2000 Newtons ut is the power output li this was done in 2 seconds? two wings tast happen for work to be done. • A force must applied to an object • The object must move in the same direction as the force. How do machines make work easier? Any change in the size of the force changes the distance. No machine can increase both force and distance. 1. Multiply force which decreases distance the load moves. 2. Multiply the distance which decreases 3. force. Or, they leave force and distance alone but change the direction in which the load moves. What is mechanical advantage? The number of times a machine multiplios the effort force. What is purpose of a machine? • To make work easier. How do machines make work easier? • They can change the amount of force • They can chango the distance (Remember that Work » Force X Distance) • They can also change the direction MORE - What are the 3 types of simple machines? • There are three simple machines: • the lever, the pulley, and the inclined plane The wheel and axle, the wedge, and the screw are modifications of the three simple machines. What is a compound (or complex) machine? • A machine made up of two or more simple machines.