Aperson riding north on a bicycle speeds up from 0 m/s to 9 m/s in 3 seconds. the acceleration of the bicycle is m/s^2.

3 m/s²

Explanation:

To calculate the average acceleration of an object  going from speed A to speed B within a certain lapse of time, we need to calculate the variance (difference) in speed divided by the time past.

What's the variation in speed?  The bicycle went from 0 to 9 m/s... so the variance in speed was of 9 m/s.

How long did the acceleration last?  3 seconds.  So....

That was the average acceleration rate of the bicycle.

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle