Answer:
50 kg m/ s²
Step-by-step explanation:
As the slope of the graph represent the force of the motorcycle, 
The graph is a straight line and the initial values of momentum and time is taken to be at origin. 
Hence , force = change in momentum / change in time
 = ΔP / ΔT
 = 500 - 0 / 10 -0
 = 50 kg m/ s²