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Work, Energy and Power — Physics STD 11 — Question

Tamilnadu BoardEnglish MediumSTD 11PhysicsWork, Energy and Power3 Marks
Question
An elevator which can carry a maximum load of 1800 kg (elevator + passengers) is moving up with a constant speed of 2 ms-1. The frictional force opposing the motion is 4000 N. Determine the minimum power delivered by the motor to the elevator in watts as well as in horse power.
✓

Answer

$
F=m g+f=22000 N
$
$\therefore$ Power supplied by motor to balance this force is :
$
P = F v=44000 W =\frac{44000}{746}=59 hp .
$

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