Question

A man is running at a speed of 4m/s toward a stationary bus when he is 6 m behind the door the bus start moving at a constant acceleration of 1.2m/s how long does it take for the man to catch the bus

Answer 1

The displacement to catch the bus => s =  vt - 6 

s = 4t - 6 [ v = 4]__________(1)

The displacement of bus = >  s = 1/2 at²

s = (6/10 )t²     ___________(2) 

comparing (1) and (2) 

4t - 6 =  0.6t²

20t  - 30  = 3t²

3t²- 20t  + 30  = 0 

time is  2.28 or 4.39 

Answer 2

HI Friend,

Here is your answer,

S= Displacement 
V=Final Velocity 
T=Time

 S => vt - 6 

S => 4t - 6 ( v = t)

Displacement of the bus will be  = >  s = 1/2 at²

S => {6/10}t²   

(1) and (2)

4t - 6 =>  0.6t²

20t  - 30  => 3t²

3t²- 20t  + 30  => 0 

TIME=> 2.28 or 4.39 



Hope it helps you!