a 1500 kg car accelerates from 0 to 25 m/s in 7.0 s. What is the average power delivered to the engine?
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Good
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To find the average power delivered to the engine, we can use the formula:
Average Power = Work / Time
First, let's calculate the work done. The work done on an object is equal to the force applied multiplied by the distance traveled.
In this case, the force is calculated using Newton's second law of motion:
Force = Mass x Acceleration
Given that the mass of the car is 1500 kg and the acceleration is (change in velocity) / (time) = (25 m/s - 0 m/s) / 7.0 s = 3.57 m/s², we can calculate the force as:
Force = 1500 kg x 3.57 m/s²
Next, we need to determine the distance traveled. We can use the kinematic equation:
Distance = Initial velocity x time + (1/2) x acceleration x time²
Since the car starts from rest (0 m/s), the initial velocity is 0 m/s. Substituting the values, we have:
Distance = 0 m/s x 7.0 s + (1/2) x 3.57 m/s² x (7.0 s)²
Now that we have the force and distance, we can calculate the work:
Work = Force x Distance
Finally, we can calculate the average power by dividing the work by the time:
Average Power = Work / Time
Let's plug in the values and calculate the answer.
Power=change in KE/time
= (.5m(vf^2-Vi)^2)/7sec