Answer:
Acceleration,

Step-by-step explanation:
It is given that,
A car moving south speeds up from 10 m/s to 40 m/s in 15 seconds.
It means,
Initial velocity of the car, u = 10 m/s
Final velocity of the car, v = 40 m/s
Time taken, t = 15 seconds
We have to find the acceleration of the car. Mathematically, acceleration of the car is given by taking difference in velocities divided by time taken i.e.



Hence, this is the required solution.