Question

Two cars A and B are at rest at same point initially. If a starts with uniform velocity of 40 metre per second and B starts in same direction with constant acceleration of 4 metre per second square ,then B will catch A after how much time ?

how to do this ques. with the concept of relative velocity??​

Answer 1

Answer:

Let distance covered by A be S  

1

Let distance covered by B be S  

2

​B will catch A when S  

1

​  

=S  

2

​  

 

S=ut+1/2×a×t  

2

 

Therefore from given data,

40t+(1/2×0×t  

2

)=0t+1/2×4×t  

2

 

40t=2t  

2

 

20t=t  

2

 

t=20s