Respuesta :

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.