## How much Work?

**1) How much work does an elevator motor do to lift a 1000 kg elevator a height of 100 m?**

**Known variables:**

**mass (m): 1000 kg**

**height (h): 100m**

**Work = Force x Distance**

We need to find a force. Since there is gravity, all we have to do is multiply it by the mass to get the Force.

1000 x 9.81 = 9810N

**w** = f x d, so w = 9810 x 100 = 981000 Joules.

=9.8×10

^{5}J**2) How much power must the motor supply to do this in 50 s at constant speed?**

**Power **= work / time.

**P** = 981000/50 = 19620 watts.

=2.0×10

^{4}W
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