Mass of the car `A, m_A = 1000kg`
Mass of the car `B, m_B = 1000kg`
initial velocity of car `A, u_A= 36 km//h = 36 ((5)/(18))m//s = 10m//s (as 1km//h = (5)/(18)m//s)`
Opposing force of friction, `F = 100 N`
Power of the engine of car `A = F u_A = (100N) (10m//s) = 1000 W`
`("as power" ="force" x "velocity"` and `N m//s = J//s =W)`
Initial velocity of car `B, u_B = 0`
Final velocity of car `A, upsilon_A = 0 ("as it comes to rest after colliding with car B")`
If `upsilon_B` is final velocity of car B when car A collides with it applying the law conservation of momentum,
initial momentum of cars A and B = final momentum of cars A and B
`i.e., m_A u_A + u_B u_B = m_A upsilon__B`
or `1000 xx 10 + 1000 xx 0 = 1000 xx 0 + 1000 xx upsilon_B`
or `upsilon_B = 10m//s`