Question

A cyclists is travelling at 15ms-1 she applies brakes so that she does not collide with a wall 18m away. What deceleration must she have.

Answer 1

deceleration is -6.25m/s

Answer 2

Answer: The correct answer is $a= -6.25 meter per second square$.

Explanation:

The expression for the equation of motion is as follows;

$v^{2}-u^{2}=2as$

Here, v is the final velocity, u is the initial velocity, s is the distance and a is the acceleration.

It is given in the problem that A cyclists is travelling at 15 meter per second she applies brakes so that she does not collide with a wall 18 m away.

Put v= 0, u= 15 m/s and s= 18 m.

$(0)^{2}-(15)^{2}=2a(18)$

$a= -6.25 meter per second square$

Therefore, the value of deceleration is $a= -6.25 meter per second square$.