Unreasonable Results (a) Repeat Exercise 4.29, but assume an acceleration of 1.20 m/s2 is produced. (b) What is unreasonable about the result? (c) Which premise is unreasonable, and why is it unreasonable?

Exercise 4.29:

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?

Problem 38PE

Solution 38 PE

Step 1 of 4:

In this question , we need to find total force required to resist the motion of the car , boat and trailer

And explain the unreasonability about the result

Check which premise is unreasonable and explain the reason for it be unreasonable

Data given

Mass of car

Mass of boat and trailer

Force exerted by the car on the road

Acceleration

Step 2 of 4 :

Let us denote the total resisting force as

We shall find the total mass of car, trailer and boat

It is obtained by

The net force is given by

Substituting values we get

Thus we have net force as