Work and
Power
Assignment
I will number you into groups.
You will be working in chapter 8 of
the book.
Your group number will represent
your section of the chapter.
Expectations
You will be presenting your section to
class.
The method of presentation is your
choice. (notes, demonstrations, vocab
game…)
Your group will also generate 5 test
questions (multiple guess / calculations)
Work
Work – a force applied over a
distance
W= F(d)
units: F=Newton d=meter
W= Joules
W=Fxd
Therefore:
You must have MOTION in order to
have work… something has to
change position
Power
Power – the rate at which work
is done
Power = Work/time
Unit is Watt (joule/second)
Example Problems
If a 450 N boulder is
dropped 2.4 m in 25
seconds, how much power
is exerted on the object?
Example Problems
How much work is done by a toy
car with an applied force of 12
N which is moved for 39 m?
The weight lifter lifted a mass of 100
kg (barbell) over her head in 5.21
seconds. Approximately how much
power did she generate in raising the
barbell?
Example Problems
A mechanic used a hydraulic lift to
raise a 12,054 N car 1.89 m above
the floor of a garage. It took 4.75 s
to raise the car. What was the
power output of the lift?