A car moving with a speed of 90kmh-1 was brought uniformly to rest by the application of the brakes in 10s. How far did the car travel after the brakes were...
A car moving with a speed of 90kmh-1 was brought uniformly to rest by the application of the brakes in 10s. How far did the car travel after the brakes were applied?
Answer Details
The question describes a car that is initially moving with a speed of 90 km/h, and then brought to a stop by the application of the brakes in 10 seconds. To find the distance traveled by the car during this time, we can use the formula:
distance = (initial velocity * time) + (0.5 * acceleration * time^2)
where initial velocity is the velocity of the car before braking, time is the duration of the braking, and acceleration is the deceleration of the car due to the braking.
We can convert the initial velocity from km/h to m/s by multiplying it by 1000/3600, which gives 25 m/s. We know that the car was brought uniformly to rest, so its acceleration is simply its initial velocity divided by the time it took to come to a stop, or:
acceleration = initial velocity / time
Plugging in the given values, we get:
acceleration = 25 / 10 = 2.5 m/s^2
Now we can plug in the values of initial velocity, time, and acceleration into the distance formula to get:
distance = (25 * 10) + (0.5 * 2.5 * 10^2) = 125 + 125 = 250 meters
Therefore, the car traveled a distance of 250 meters after the brakes were applied. So, the correct option is (c) 250m.