Question

Two cars meet with constant acceleration 2 m/s^2 at the time that the distance between them were 175 m, the first car velocity was 15 m/s and the second car velocity was 20 m/s. After how many seconds the both cars will meet?

Answer 1

Solution:-

If both cars are moving in opposite direction,

Then total distance covered by both the cars to meet each other

S=175 m

Relative velocity or net velocity of one car with respect to second car

V=V1-(-V2) =15-(-20) =35 m/s

Let time "t" would be taken to meet both the cars.

So,  from Newton equation of motion

S=Vt+1/2 *a*t^2

175= 35*t +1/2* (2+2)*t^2

2*t^2 +35*t -175=0 (Relative acceleration , a=a1-(-a2)=2+2)

solving above equation we get

t=4.05 second.

Therefore both car will meet after 4.05 second.