28 terms

# Chapter 12 work, power,and machines

###### PLAY
different examples for work are
you work on science problems.
you got to work
raking out the tash is too much work
work is done only when a ____causes a change in the position or motion of an object in the direction of the applied force.
force
____is calculated by multiplying the ____ by the ______ over which the force was applied.
work, force, distance
the unit of work and energy was named in honor of the english physicist ____ _____ ____
James Prescott Joule
because work is calculated as ____times ____it is measured in units of newtons times meters, N•m
force, distance
A Nm can be converted into a_____.
joule
a _____is also equivalent to: 1kg•m2/s2
joule
the quantity that measures work in relation to time is _____
power
power is the ____ at which ___is done
rate, work
write the equation for power in word form:
power equals work divided by time
give the symbolic formula for power:
p=W/t
write the equation for work in word form
work equals force times distance
give the symbolic formula for work
W=F•d
whats equal to the total number of lawns mowed
work
whats equal to the rate of mowing
power
the SI unit of power is the
Watt
a ___is the amount of power required to do 1 joule of work in 1 second
Watt
work is done only when ____causes a change in the position or the motion of an object in the direction of the applied force.
force
Joule=
kg•m2/s2
Symbolic formula for power
P=W/t
units for power
Watts
A Watt is equal to a _____.
j/s
Watt
one joule of work performed in one second
Joule
equals one Newton-meter
Power
amount of work performed over time
Work
force times distance
Simple Machine
an unpowered mechanical device