Work Chapter 5.1

Work Transfer of energy that occurs when a force makes an object move 2 conditions for work to occur Object must move! Object moves in the same direction as the applied force

Was there work? Booking up books off the floor and placing them on a shelf Did the object move? Was it in the same direction as the force?

Was there work? 2. Holding books in your hands as you walk across a room? Did the objects move? Did the objects move in the same direction as the applied force?

Was there work? 3. If you push on your car but cannot budge it? Did the object move? Was the applied force in the same direction as the movement?

Work & Energy Energy is the ability to do work Energy can transfer to another by doing work on the object Example: Lifting books converts chemical energy from your muscles into PE when their height is increased

Calculating Work Work = Force x distance W = F x d J = N x m Greater force, increases work Greater distance moved, requires more work Both variables directly proportional to work

Practice Calculation A couch is pushed with a force of 75 N and moves a distance of 5 m across the floor. How much work was done on the couch? W = F x d W = 75 N x 5 m 375 J

Practice Question 2 A lawn mower is pushed with a force of 80 N. If 12,000 J of work are done in mowing a lawn, what is the total distance the lawnmower was pushed? W = F x d 12,000 = 80 x d d = 150 m