Compare the acceleration of a motorcycle that accelerates from 80 km/h to 90 km/h

Speed is a magnitude, a scalar quantity (i. e. 65 mph)

Velocity is a magnitude and direction, a vector quantity (i. e. 65 mph north)

Acceleration is the change in velocity over a unit of time

(1) Different rates of acceleration.

Given for the motorcycle:

Vi = 80 km/h

Vf = 90 km/h

Given for the bicycle

Vi = 0.0 km/h

Vf = 10 km/h

*IF * the time unit is the same (let's say 10 seconds), the actual value is the SAME for each, because the change in velocity was the same for each. 10 km/h over 10 seconds.

a = [ Vf - Vi ] / t

a = [ (90 km/h) - (80 km/h) ] / (360 h)

a = [ 10 km/h ] / (360 h)

a = 0.023 km/h^2

See, same thing, bicycle or motorcycle, change is 10 km/h, over the same time period gives the same value.

Incidentally, you should usually use meters per second (m/s) and seconds (s) not hours and kilometers.