Question

a 2000 kg car, initially at rest, is accelerated along a horizontal roadway at 3 m/s2. what is the average power required to bring the car to a final speed of 20 m/s? responses 6 x 103 w 6 x 10 3 w 2 x 104 w 2 x 10 4 w 3 x 104 w 3 x 10 4 w 4 x 104 w 4 x 10 4 w 6 x 104 w

Answer 1

The average power required to bring a 2000 kg car to a final speed of 20 m/s, when accelerated at 3 m/s^2, is 60,000 watts, or 60 kW.

Step-by-step explanation:

The question is asking to calculate the average power required to accelerate a 2000 kg car from rest to a final speed of 20 m/s with an acceleration of 3 m/s2.

To calculate the power, we need to find the work done on the car and then divide it by the time taken to reach that speed.

The work done is equal to the change in kinetic energy, which is ½(mv2) at the final speed minus ½(mv2) at the initial speed, since the car starts from rest.

The kinetic energy at 20 m/s is ½(2000kg)(20m/s)2 = 400,000 J.

We can also find the time, t, taken to reach this speed using v = u + at, where u is the initial speed (0 m/s), a is the acceleration (3 m/s2), and v is the final speed (20 m/s).

Here, t = v / a = 20/3 s.

Now, the average power is Work/time, which results in 400,000 J / (20/3 s) = 60,000 W or 60 kW.