A two-wheel drive tractor weighing $21 \mathrm{kN}$ has a wheel base of $2.1 \mathrm{~m}$. The CG of the tractor is $0.7 \mathrm{~m}$ ahead of rear axle centre. The tractor is pulling a single-axle trailer with gross trailer weight of $50 \mathrm{kN}$ on a leveled concrete road while maintaining the line of pull parallel to the ground surface. The tractor hitch point is $42 \mathrm{~cm}$ behind the rear axle centre and $52.5 \mathrm{~cm}$ above the ground surface. During operation, $20 \%$ of the gross trailer weight is transferred to the tractor hitch point. If the coefficient of rolling resistance for each of the tractor and trailer wheels is taken as $0.04,$ and their ground reactions are assumed to pass through their respective wheel centres,the dynamic ground reaction against the tractor rear wheels in $\mathrm{kN}$ is
(A) 14.0
(B) 24.0
(C) 24.5
(D) 26.4
A two-wheel drive tractor weighing $21 \mathrm{kN}$ has a wheel base of $2.1 \mathrm{~m}$. The CG of the tractor is $0.7 \mathrm{~m}$ ahead of rear axle centre. The tractor is pulling a single-axle trailer with gross trailer weight of $50 \mathrm{kN}$ on a leveled concrete road while maintaining the line of pull parallel to the ground surface. The tractor hitch point is $42 \mathrm{~cm}$ behind the rear axle centre and $52.5 \mathrm{~cm}$ above the ground surface. During operation, $20 \%$ of the gross trailer weight is transferred to the tractor hitch point. If the coefficient of rolling resistance for each of the tractor and trailer wheels is taken as $0.04,$ and their ground reactions are assumed to pass through their respective wheel centres,the dynamic ground reaction against the tractor rear wheels in $\mathrm{kN}$ is
(A) 14.0
(B) 24.0
(C) 24.5
(D) 26.4