w ork and p ower. w arm u p 1. which of the liquids in the graduated cylinder below is the least...
TRANSCRIPT
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