A 1100-kg car pulls a boat on a trailer. (a) what total force resists the motion of the car, boat, and trailer, if the car exerts a 1900-n force on the road and produces an acceleration of 0.550 m/s2? the mass of the boat plus trailer is 700 kg. (b) what is the force in the hitch between the car and the trailer if 80% of the resisting forces are experienced by the boat and trailer?

Refer to the diagram shown below.

R = total resistive force.

80% of this force is experienced by the boat and trailer.

T = the force in the hitch between the car and the trailer.

Overall motion:

Total mass = 1100 + 700 = 1800 kg

Acceleration = 0.55 m/s²

Driving force = 1900 N

Resisting force = R N

Therefore

(1900 - R N) = (1800 kg) * (0.55 m/s²)

1900 - R = 990

R = 910 N

0.2R = 182 N

0.8R = 728 N

Consider the motion of the car:

Driving force = 1900 N

Resistive force = 0.2R = 182 N

Force in the hitch = T NAcceleration = 0.55 m/s²

Mass = 1100 kg

Therefore

1900 - 0.2R - T = 1100*0.55

1900 - 182 - T = 605

T = 1113 N

Answer:

R = 910 N, the total resistive force.

T = 1113 N, the force in the hitch between the car and trailer.