Work When a force causes an object to MOVE in the DIRECTION of the force. Force Motion Calculated using the equation: Force x Distance F x d Units Newton x meter N·m Joules (J) Was work done? Marla pushes a box across the hall. – – – – Was a force applied? Did the object move as a result of that force? Did the movement go in the direction of the force? Yes to all Work Was Done Marla carries a box across the hall. – – – – Was a force applied? Did the object move as a result of that force? Did the movement go in the direction of the force? Yes, No, No Work was not done HOW MUCH WORK? A man applies a force of 500 N to push a truck through a distance of 100m. How much work does he do? 500 x 100 : 50,000 Joules Now how much? Suppose you lift a 75 N bowling ball 2 m off the floor. How much work do you do? 75 x 2 = 150 Joules One more time How much work is required to lift two 50 N bowling balls 1 m off the floor? (50 + 50) x 1 = 100 Joules Now your turn to practice Please place some yarn around your book. Make sure it is tied. Place the yarn on the spring scale hook. Pull the book slowly across the table using the spring scale. (This measures force) Measure the time it took you to pull the book and measure the distance the book traveled. You can now calculate work and power. Write all data in your journals. Thank you Your work is done here today. You will complete a worksheet on the meaning of work in class tomorrow.