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 2.20 hp. It is 92.0% ...
- physics - A 120-V motor has mechanical power output of 3.20 hp. It is 81.0% ...
- Physics - A 120-V motor has mechanical power output of 2.00 hp. It is 82.0% ...
- physics - An electric motor develops 73 kW of power as it lifts a loaded ...
- PHYSICS. - 5. A motor lifts a 12 kg mass to a height of 15 m at a constant ...
- Physics - An electric motor develops 70 kw of power as it lifts a loaded ...
- Physics - a motor lifts a 12 kg mass to a height of 15 meters at a content ...
- physics - An electric motor runs at a constant rotational frequency of 3000 r/...
- algebra - The power (P) required to run a motor is equal to the voltage (E) ...

More Related Questions