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.

To calculate the current drawn by the electric motor, we can use the formula for electrical power:

Power (P) = Voltage (V) × Current (I)

Since the problem does not provide the voltage, we need to find it using the given information. We can rearrange the power formula to solve for current:

I = P / V

First, let's calculate the power supplied to the motor.

The work done by the motor is given by:

Work (W) = Force (F) × Distance (d)

The force exerted can be calculated using Newton's second law:

F = m × a

The weight is given by:

Weight (W) = mass (m) × gravitational acceleration (g)

So, the force exerted by the motor is:

F = W = 210 N

The distance traveled is provided in the problem as 3.5 m.

The work done by the motor is then:

W = F × d = 210 N × 3.5 m = 735 J

Now, since the motor is 90% efficient, it means that only 90% of the supplied energy ends up as mechanical work. Therefore, the power supplied to the motor is:

Power Supplied = Work / Efficiency
Power Supplied = 735 J / 0.9 = 816.67 J

Finally, to find the current drawn by the motor, we need to know the voltage. Once we know the voltage, we can use the power formula to calculate the current.

Therefore, without knowing the voltage, it is not possible to determine the current drawn by the motor.