An elevator 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 horse power delivered by motor to the elevator.

An elevator can carry a maximum load of 1800 kg (elevator + passengers

1.	An elevator 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 horse power delivered by motor to the elevator.
Answer» Solution :The downward force on the elevator is `F = mg + F_f = (1800 xx 10) + 4000 = 22000 N`. The motor MUST supply enough power to BALANCE this force. Hence, `P= vecF . vecv = 22000 xx 2 = 44000 W. `