Chapter 4, Problem 20Q

To determine

Why the stopping distance of a truck much shorter than for a train going the same speed.

Answer to Problem 20Q

Solution:

By kinetic friction and due to Newton’s second law the train will take a longer distance to stop.

Explanation of Solution

Stopping distance i.e. the kinetic friction is lower for a train than a truck. It shows train has less friction when it is moving on the rails. That’s why the time to go from velocity v

to zero velocity i.e. at rest by the train takes a much longer time than a truck for which a frictional force is larger.

There is one more reason that the train is much heavier than the truck if the equal stopping force is applied on both then according to Newton’s second law the negative acceleration of the train is smaller than the truck. Thus, the train will take a longer distance to stop.