A CAR OF MASS 800KG ATTAINS A SPEED OF 25M/S IN 20 SECS. THE POWER DEVELOPED IN THE ENGINE IS

• A. 1.25 x 10⁴ W
• B. 2.50 x 10⁴ W ✓
• C. 1.25 x 10⁶W
• D. 2.50 x 10⁶ W

 

The answer to the question is: B. 2.50 x 10⁴ W

To calculate the power developed in the engine of a car, we can use the formula:

Power = Force × Velocity

First, we need to find the force acting on the car. We can use Newton’s second law of motion, which states that force is equal to mass times acceleration:

Force = Mass × Acceleration

Given:

Mass (m) = 800 kg

Initial velocity (u) = 0 m/s (assuming the car starts from rest)

Final velocity (v) = 25 m/s

Time taken (t) = 20 s

We can calculate the acceleration using the formula:

Acceleration = Change in velocity / Time

taken Acceleration = (v – u) / t

Acceleration = (25 m/s – 0 m/s) / 20 s

Acceleration = 1.25 m/s^2

Now, we can find the force acting on the car:

Force = Mass × Acceleration

Force = 800 kg × 1.25 m/s^2

Force = 1000 N

Next, we can calculate the power developed in the engine using the formula:

Power = Force × Velocity

Power = 1000 N × 25 m/s

Power = 25000 W

Therefore, the power developed in the engine is 25000 watts or 2.50 x 10⁴ W.