A car has 400 kgm/s worth of momentum and runs into a truck initially at rest. After the collision, the truck has 500 kgm/s worth of momentum. What must be the final momentum of the car and truck combined? A. 500 kgm/s
B. 100 kgm/s
C. 400 kgm/s
D. -100 kgm/s

a coal burning power plant

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s

i think it would be 5