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Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0-V batteries of a 708-kg electric car be able to supply to accelerate from rest to 14 m/s in 1.00 min?

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Final answer:

To find the current required by the batteries to accelerate the electric car, we can use the principle of conservation of energy. The electrical power supplied by the batteries will be converted into kinetic energy to accelerate the car. By calculating the expression, we find that the current required by the batteries to accelerate the electric car is approximately 545 A.

Step-by-step explanation:

To find the current required by the batteries to accelerate the electric car, we can use the principle of conservation of energy. The electrical power supplied by the batteries will be converted into kinetic energy to accelerate the car.

First, let's calculate the change in kinetic energy of the car:

Kinetic Energy (KE) = 0.5 * mass * velocity^2

ΔKE = KE_final - KE_initial

Next, we need to find the work done by the motor to accelerate the car:

Work (W) = ΔKE

Since the motor has an efficiency of 95%, we can calculate the electrical power needed:

Electrical Power = W / efficiency

Finally, using Ohm's Law (V = I * R), we can find the current:

Current (I) = Electrical Power / Voltage

Plugging in the values, we have:

ΔKE = 0.5 * 708 kg * (14 m/s)^2 - 0.5 * 708 kg * (0 m/s)^2

W = ΔKE = 0.5 * 708 kg * (14 m/s)^2

Electrical Power = W / efficiency = 0.5 * 708 kg * (14 m/s)^2 / 0.95

Current = Electrical Power / Voltage = (0.5 * 708 kg * (14 m/s)^2 / 0.95) / 12 V

By calculating the expression, we find that the current required by the batteries to accelerate the electric car is approximately 545 A .

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