Homework Help: Physics 8B

Posted by HELP on Sunday, September 18, 2011 at 2:37pm.

A 280 electric motor is 90% efficient, meaning that 90% of the energy supplied to it ends up as mechanical work.

If the motor lifts a 210 weight at 3.5 , how much current does it draw?
Express your answer using two significant figures.
I= ? Amps

Physics 8B - Henry, Tuesday, September 20, 2011 at 7:12am
No units are given; therefore, I'll have to make some assumptions:

Wt = 210 Newtons @ 3.5m/s.
280 Volt motor

Power = 210 * 3.5m/s = 735 Watts output

Power Input = Po / 0.9 = 735/0.9 = 817
Watts.

P = V*I,
I = P / V = 817 / 280 = 2.9 Amps.

Answer this Question

Related Questions

Physics 8B - A 280 electric motor is 90% efficient, meaning that 90% of the ...
physics - A 120-V motor has mechanical power output of 3.20 hp. It is 81.0% ...
Physics - An electric motor has 72 turns of wire wrapped on a rectangular coil, ...
Physics - A diagram represents a simplified sketch of an electric DC motor.which...
Physics - A 120-V motor has mechanical power output of 2.00 hp. It is 82.0% ...
college - a 200 L electric water heater uses 15 kW of electric power. If the ...
physics - A skier of mass 74 kg is pulled up a slope by a motor-driven cable. (a...
Physics Rotaional Kinetic Energy - A car is designed to get its energy from a ...
physics - A car is designed to get its energy from a rotating flywheel with a ...
physics - A car is designed to get its energy from a rotating flywheel (solid ...

For Further Reading

First Name:
School Subject:
Answer: