Question
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 $1.20 \textrm{ m/s}^2$? The mass of the boat plus trailer is 700 kg. (b) What is unreasonable about the result? (c) Which premise is unreasonable, and why is it unreasonable?
1. $-260 \textrm{ N}$
2. The friction force is in the direction of motion. This is not possible.
3. The acceleration can not be this large with only a 1900 N force from the car.
Solution Video