The equation is a Dv Dt vf - vi tf - ti. Plugging in the numbers you get the following. The deceleration will be computed by dividing the final velocity minus the initial velocity by the amount of time is taken for this drop in velocity.
You are cruising along in a bike race going a steady 10 meters per second 10 ms.
Thus the formula is. Use the formula to find acceleration. A is acceleration in mss or ms 2. Where D v is the change in velocity and D t is the change in time.