I WILL MARK BRAINLIEST! An 200 kg car is traveling at 5 m/s when it collides with a stationary car of mass 600 kg. What is their combined velocity after the collision if the brake is off and they adhere to one another after the collision?

Explanation: law of conservation of momentum  

Initial Momentum = Final Momentum

So, first we calculate initial momentum of the system:

Initial Momentum  = m1*u1 + m2*u2

and we are given

m1 = mass of car = 600 kg

m2 = mass of van = 400 kg

u1 = Initial Speed of Car  

to find the initial speed we use equation of motion

Vf = Vi + at

Vf = 0 m/s + (0.2 m/s²)(60 s)

Vf = u₁ = 12 m/s  

u₂ = Initial Speed of Van = 0 m/s

Therefore,

Initial Momentum  = (600 kg)(12 m/s) + (400 kg)(0 m/s)

Initial Momentum  = 7200 Ns   (1)

final momentum = m₁v₁ + m₂v₂

where,

v₁ = v₂ = final speed of car+van (both locked ) = 7.2 m/s

Therefore,

Final Momentum = (600 kg)(7.2 m/s) + (400 kg)(7.2 m/s)

Final Momentum = 7200 Ns   (2)

on comparing (1) and (2)