Let’s let acceleration be the variable a. We know that Force = Mass x Acceleration, so if we rewrite the equation, A = Force/Mass.
A = 18,000N / (2100 kg + 2500 kg) = 3.91 m/s^2.
To find the force of the trucks bumper, we take the mass and multiply it by the acceleration. F (Truck Bumper) = 2100 x 3.9 = 8217.4 N
Same idea to find the force of the SUV bumper ->
F = 2500* 3.9 = 9775 N.