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24/10/2021 7:28 pm
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A cyclist is travelling at 15 m s-1. She applies brakes so that she does not collide with a wall 18 m away. What deceleration must she have?
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24/10/2021 7:32 pm
Initial velocity, u = 15m/s
Final velocity, v = 0 m/s
Distance, s = 18 m
Acceleration, a = ?
Using relation, \(v^2 - u^2\) = 2as
02 - (15)2 = 2a x 18
-225 = 36a
a = \(\frac{-225}{36}\) = -6.25 m/s2
So, deceleration is 6.25 m/s2.