Imagine that your poorlybehaved pet dog pulls very hard on h

Imagine that your poorly-behaved pet dog pulls very hard on his leash while you go for a walk. To keep him from running away, do you have to pull in the opposite directly just as hard? Explain.

Solution

I will have to apply slightly less amont of pull in opposite direction to keep him running away because when pet dog is applying force in forward direction, there is friction force acting in opposite direction which will restrict him from running. So, magnitude of force need to be apply to stop him for running is give by:

Force required to apply = pulling force applied by dog - friction force