3 1) In science, work occurs when a force causes an object to move in the direction of the force. Work has happened because the box moved
4 2) Work is done whenthe object moves as the force is applied andb) the direction of the object’s motion is the same as the direction of the force applied.
5 3) Work can be calculated: W=F x dWork equals force times distance
6 4) Force is measured in Newtons, and distance is measured in meters: so the unit for work is the Newton-meter or the joule.
7 5) Calculating work:a) A man applies a force of 500N to push a truck 100m down the street.How much work does he do?
8 1- You lift a 75N bowling ball 2 m off the floor b) In which situation do you do more work?1- You lift a 75N bowling ball 2 m off the floor2- You lift two 50 N bowling balls 1m off the floor.
9 Complete the following work problems Complete the following work problems. The first one has been done as an example for you.Work (J) = Force (N) X Distance (m)1. 20J = 10N X 2m2. 20J = force? X 2m3. work? = 10N X 50m4. work? = 0.5N X 600m5. 500J = 500N X distance?6. work? = 80N X 7m
10 the units for power are the watt (W) 6) Power is how fast work is done. It can be calculated:P=W/tthe units for power are the watt (W)
11 a) work is done in less time, or b) the amount of work is increased. 7) Power is increased ifa) work is done in less time,or b) the amount of work is increased.Review game
18 1) All machines are made from six simple machines: the lever, inclined plane, wedge, screw, pulley, and wheel and axle.
19 2) Levers: a bar that pivots at a fixed point called a fulcrum A) First class levers: fulcrum between the input force and load (see-saw)B) Second class levers: load between the fulcrum and the input force (wheel barrow)C) Third class levers: input force between the fulcrum and the load (hammer)
20 3) Inclined Plane: straight slanted surface - the longer the plane the greater the mechanical advantage (ramp)
21 4) Wedges: double inclined plane that moves (knife, axe head, or door stop)