Work and Power Work l Work happens when
- Slides: 17
Work and Power
Work l Work happens when a force moves an object over a distance l If the object does not move, no work is done l For work to be done, the direction of the applied force must be the same as the direction of the motion
Work l You lift a bag of groceries from the trunk of your car l Is work being done? l You are using force to lift the bag of groceries, and the force is in the direction of the motion
Work l You carry a bag of groceries from the car to the kitchen l Is work being done? l You are using force to carry the groceries l Is the force being applied in the direction of the motion?
Calculating Work l Work = force x distance moved l W=FΔd (on your reference table!) l Units of work are N·m, l Also known as the joule l Abbreviated J l Set up the triangle!
Calculating Work Force Distance
Work Practice l 60 N of force is used to move an object a distance of 4. 0 m. How much work has been done on the object?
Work Practice l When you pick up your backpack, you do 58 J of work to lift it up 1. 3 m to put it on your back. What is the force on the backpack?
Work Practice l. A tow truck tows your car 2200 m to the nearest service station. If the truck did 2, 970, 000 J of work to tow the car, what was the force on the car?
Work Practice l. A crane lifts a steel beam with 5200 J of work. If the force on the beam is 240 N, what is the distance the beam has been lifted?
Power l
The Power Triangle Work Power Time
Power l Where have you heard of watts before? l Electrical energy l Light bulbs l Can you explain why a bulldozer has more power than a person with a shovel? l Work and Power Tune
Calculating Power l Espen and Deion push a sofa across a room in 16 seconds using 142 J of work. How much power did they use?
Calculating Power l KJ uses 72 J of work to push a textbook across the table. He uses 432 W of power. How long did it take him to move the book?
Calculating Power l Aniké and Alanah move the lab table for 3 seconds using 98 W of power. How much work did they do?
Calculating Power l Brynne throws a 12 N softball 4 m in 1. 8 s. How much power has she used on the softball?
Power triangle diagram
What happens when weathering and erosion work together?
In pairs discuss the following statements
Solar power satellites and microwave power transmission
Actual power and potential power
Dispersive power of grating unit
Catcher in the rye chapter 13 analysis
Romeo and juliet sunday
Romeo and juliet act 4 scene 2 summary
Charging by contact example
Romeo and juliet act 3 script
Biogeochemical cycles quiz
What happens in chapter 11 in lord of the flies
Contrast between what is expected and what actually happens
Romeo and juliet act 5 characters
Doge -coin
It tells how something works or why something happens
Wave behavior reflection
