Answer:
-2.5 m/s²
Step-by-step explanation:
The acceleration of a body is the change in it's velocity with time.
The change in velocity with time can be obtained as the slope of a velocity time graph ;
Acceleration = (change in velocity / change in time)
Taking the slope :
Change in Velocity = △y = y2 - y1
Change in time = △x = x2 - x1
(10, 15) ; (0, 40)
△y / △x = y2 - y1 / x2 - x1 = (40 - 15) / (0 - 10)
△y / △x = 25 / - 10 = - 2.5 m/s²