A car moving with a speed of 180km/h was brought uniformly to rest by the application of the breaks in 20s. How far did the car travel after the breaks were applied?
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Finial velocity = v= 0. t= 20s s=(v+u)/2 ×20s 180km/hrs = 50m/h s={0+50)/2×20 = 500
there are 3600 s in an hr
180 km/h = 50 m/s
the average velocity during the stop is ... (50 + 0) / 2
the stopping distance is
... 25 m/s * 20 s
To find the distance traveled by the car after the brakes were applied, we can use the equation:
distance = initial velocity * time + (1/2) * acceleration * time^2,
where:
- initial velocity is the velocity of the car before the brakes were applied,
- time is the time taken for the car to come to a rest, and
- acceleration is the deceleration due to the brakes.
First, we need to convert the speed from km/h to m/s, as the SI unit of speed is meters per second. The conversion factor is 1 km/h = 0.2778 m/s. Let's calculate the initial velocity in m/s:
Initial velocity = 180 km/h * (0.2778 m/s / 1 km/h) = 50 m/s.
Given that the time taken for the car to come to rest is 20 seconds, and since the car is brought uniformly to rest, the final velocity is 0 m/s. Therefore, the acceleration can be calculated using the equation:
acceleration = (final velocity - initial velocity) / time.
Since the final velocity is 0 m/s, the equation simplifies to:
acceleration = - initial velocity / time.
Substituting the values, we get:
acceleration = - 50 m/s / 20 s = -2.5 m/s^2.
Now, we can use the equation for distance to find the distance traveled by the car:
distance = 50 m/s * 20 s + (1/2) * (-2.5 m/s^2) * (20 s)^2.
Simplifying this equation, we get:
distance = 1000 m - 500 m = 500 m.
Therefore, the car traveled a distance of 500 meters after the brakes were applied.