Answer:
32.5 ms⁻¹
Explanation:
Theory
The law of conservation of linear momentum
The sum of linear momentum of a system under no external force remains constant.
In this scenario although different forces act on two vehicles by each other when we consider the total system of two cars no external unbalance force act on them. So we can apply this law.
As law says,
The sum of linear momentum before collision = The sum of linear momentum after collision.
Momentum = mass × velocity
1000×40+3000×35 = 1000×v + 3000×37.5
where v = velocity of the red car after the cash
v = 32.5 ms⁻¹
