A motorcyclist travelling at 30m/s starts to apply his brake when he is 50m from the traffic light that has just turned red .if he reached the traffic light. what is the deceleration a

9m/s²

Explanation:

Given parameters:

Initial velocity  = 30m/s

Final velocity  = 0m/s

Distance traveled  = 50m

Unknown:

Deceleration  = ?

Solution:

To solve this problem, we apply the proper motion equation;

          V²   = U²   +  2aS

V is the final velocity

U is the initial velocity

a is the acceleration

S is the distance

  Insert the parameters and solve;

          0²  = 30²  + 2(a)50

          -900  = 100a  

              a = -9m/s²

The negative value indicates deceleration.

The motorcycle decelerates at a rate of 9m/s²

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

massxgravity x heght=weightxheight= pe

4900=490xh

h=10