Answer:
[tex]f=101.5N[/tex]
Explanation:
The frictional force opposes the relative motion between the vehicle and the lunar surface. Thus, its sign is contrary to the drive force. According to Newton's second law:
[tex]\sum F=ma\\\sum F=F_d-f\\ma=F_d-f[/tex]
Rewriting for f:
[tex]f=F-ma\\f=1.42*10^3N-(5.86*10^3kg)(0.225\frac{m}{s^2})\\f=101.5N[/tex]