Date post: | 19-Dec-2015 |
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WARM UP1. Which of the liquids in the graduated cylinder
below is the least dense?2. Which is the most dense?3. Estimate the density of Liquid C.4. Calculate the density of a metal block with a
mass of 40 grams and a volume of 5 milliliters.
WHAT IS WORK?
• Work is done when a force causes an object to move in the direction of the force.• The force and the direction of movement must
be parallel• Always involves a transfer of energy
worknot work
• Applying a force doesn’t always mean that work is done.• Example: if you push against a wall for an
hour, and it doesn’t move, you haven’t done work
Example Direction of force
Direction of motion
Doing work?
Pushing a box
Walking with your backpack on
Lifting a bag of groceries
Carrying a bag of groceries
Work = force x distanceForce applied to an object (in newtons)Distance the object moves (in meters)
Work is measured in Joules (like energy)
Path 1: exert less force over a longer distance Path 2: exert more force over a shorter distance
Same amount of work done for each path
WORK, ENERGY, AND POWER IN HOCKEY
http://science360.gov/obj/video/c5be5456-2e39-49a7-8118-218868df89eb/work-energy-power