Question

A motor car travels at a constant velocity of 10m for 15 seconds and then accelerates at 0,5 m² for 10 seconds .calculate the final velocity

Answer 1

To calculate the final velocity, we need to calculate the distance traveled in each phase and then use that information to find the final velocity.

1) In the first phase, the car travels at a constant velocity of 10m for 15 seconds. Since the velocity is constant, the distance traveled is given by v * t, where v is the velocity and t is the time. Therefore, the distance traveled in the first phase is 10m/s * 15s = 150m.

2) In the second phase, the car accelerates at 0.5 m² for 10 seconds. We can use the equation of motion d = v0t + (1/2)at², where d is the distance traveled, v0 is the initial velocity, t is the time, and a is the acceleration. Since the car starts from rest, the initial velocity is 0m/s, so the equation simplifies to d = (1/2)at². Plugging in the values, we get d = (1/2)(0.5 m/s²)(10s)² = (1/2)(0.5 m/s²)(100s²) = 25m.

Now, to find the final velocity, we add the distances traveled in each phase and divide by the total time:
Total distance = 150m + 25m = 175m
Total time = 15s + 10s = 25s
Final velocity = total distance / total time = 175m / 25s = 7 m/s

Therefore, the final velocity of the motor car is 7 m/s.