Answer:1265 N
Explanation:
Given
acceleration of motorcycle [tex]\left ( a\right )=3.5 m/s^2[/tex]
Velocity [tex]\left ( v\right )=90 km/h\approx 25m/s[/tex]
Air friction and Friction[tex]\left ( f\right )=425 N[/tex]
mass of the motorcycle with rider[tex]\left ( m\right )=240 Kg[/tex]
Applying Forces on motorcycle
[tex]F_{engine}-f=ma[/tex]
[tex]F_{engine}=f+ma[/tex]
[tex]F_{engine}=425+240\left ( 3.5\right )[/tex]
[tex]F_{engine}=425+840=1265 N[/tex]