Question

Suppose a 1,000kg car is being driven at 30m/s. The driver then steps on the brakes, which apply a constant frictional force of 2500N over a distance of 100m. Determine the speed of the car at the end of the 100m.(6)

Answer 1

The speed of the car at the end of 100m is 8.66 m/s.

Step-by-step explanation:

To determine the speed of the car at the end of 100m, we need to calculate the deceleration of the car using the given information. First, we can calculate the initial velocity of the car in m/s by converting 30 m/s to m/s. The initial velocity is 30 m/s. Next, we can use the formula v^2 = u^2 + 2as to calculate the deceleration, where v = final velocity, u = initial velocity, a = acceleration (which is the deceleration in this case), and s = distance. Rearranging the formula, we have v^2 - u^2 = 2as. Plugging in the values, we get v^2 - (30^2) = 2(-2500)(100). Solving for v, we find that v = 8.66 m/s. Therefore, the speed of the car at the end of 100m is 8.66 m/s.