Question

At t = 0 seconds, a cart is moving with a velocity of 10 cm/s and an acceleration of 4.0 (cm/s)/s. Assuming its acceleration stays at this value, what will its velocity be 7.0 seconds later?

Answer 1

For this case what you should do is write the kinematic equations to find the final speed.
We have then:
a = a
vf = a * t + vo
Where,
vf: final speed
a: acceleration
t: time
vo: initial speed.
Substituting the values we have:
vf = (4.0) * (7.0) + (10)
vf = 38 cm / s
answer:
its velocity will be 38 cm / s 7.0 seconds later