A motorcycle is moving at 30 m/s when the rider applies the brakes, giving the motorcycle a constant deceleration. During the 3.0 s interval immediately after braking begins, the speed decreases to 15 m/s. What distance does the motorcycle travel from the instant braking begins until the motorcycle stops?
The motorcycle takes three seconds to decelerate to half speed. Its deceleration is constant, So it should take 6 seconds to stop. The Deceleration is a change of 30 m/s in 6s, so 30/6 5 m/s/s. Because it is decelerating, the acceleration is -5m/s/s. Use the motion formula S(U*T)+(0.5*A*T^2) (S Equals U times T Plus Half Times A Times T Squared) Where: S Distance Traveled (The answer we're looking for) U Original Velocity (30m/s) T Time (6s) A Acceleration (-5m/s/s) Put in values and solve: SUT+0.5AT^2 S(30*6)+(0.5*-5*6^2) S180+(-2.5*36) S180+-90 S180-90 S90 Meters The Answer is 90 Meters
