P
Fd
t
P
(1890 lbf)(1455 ft)
5 sec
1 hp
550 ft lbf/sec
P
1000 hp
P
Fv
550
P
(1890 lbf)(291 ft/sec)
550
P
1000 hp
Power
work done
time required
Energy, Work, and Power
POWER
Rev. 0
Page 11
CP-05
Example 3:
A race car traveling at constant velocity can go one quarter mile (1455 ft) in 5
seconds. If the motor is generating a force of 1890 lbf pushing the car, what is the
power of the motor in hp? Assume the car is already at full speed at t=0.
or
Summary
The main points of this chapter are summarized below.
Power Summary
+
Power is the amount of energy used per unit time.
+
