Final answer:
The total resisting force for the car, boat, and trailer system is 910 N, and 80% of this, which is 728 N, is experienced by the boat and trailer, representing the force on the hitch.
Step-by-step explanation:
To solve part (a) of the student's question, we need to calculate the total resisting force experienced by the car, boat, and trailer system. The total mass of the system (the car plus the boat and trailer) is 1100 kg + 700 kg = 1800 kg. According to Newton's second law, force equals mass times acceleration (F = m × a), so the total force exerted by the car is the mass of the system times the given acceleration.
Using the provided values, the total force exerted is 1800 kg × 0.550 m/s² = 990 N. This is the net force acting on the system. The question also tells us that the car exerts a 1900-N force on the road. To find the resisting force, we subtract the net force from the force applied: resisting force = 1900 N - 990 N = 910 N.
For part (b), we need to find the force on the hitch between the car and the trailer. We know that 80% of the resisting force is experienced by the boat and trailer, so we calculate 80% of 910 N, which equates to 728 N. The hitch force is the resisting force experienced by the boat and trailer.