WOLFRAM|DEMONSTRATIONS PROJECT

Power versus Work

​
mass m
44
time t
4.45
release system
W = m g d
= 44 × 9.8 × 10
= 4312.00
P = W ÷ t
= 44 × 9.8 × 10 / 4.45
= 968.99

Work is defined to be the product of force over the distance it is applied. In symbols,
W=F×d
, where
W
is the work,
F
is the force, and
d
is the distance.

Power,
P
, is work per unit time, so
P=W/t
, where
t
is time.

This Demonstration calculates the work and power needed to lift a mass
m
through a height
d
in time
t
. The darkness of the blue box indicates its mass. The distance is fixed to be
d=10
and
g=9.8
, the standard SI measurement for gravity. In this situation, Newton's second law,
F=ma
, where
a
is acceleration, becomes
F=mg
. Substituting for
F
in the first equation gives
W=mgd
.