B How Can You Model a Man Sliding on Rough Ice with Intermittent Pushing?

[walking]

How would you model the following situation?

A man of mass m slides on rough ice with coefficient of kinetic friction $\mu_k$, while pushing outwards at intervals to try to come to a stop in a shorter time.

For example, he might slide for 5 seconds then push out with his right foot, then slide for 3 seconds then push out with his left foot, etc.

I am finding difficulty modelling this. I am only able to model the situation where the man slides freely.

 

[A.T.]

...while pushing outwards at intervals to try to come to a stop in a shorter time...

What does "pushing outwards" mean? And why should it slow him down?

I am only able to model the situation where the man slides freely.

Show your work.

 

[osilmag]

What is the equation for the force of friction?

How would you sum the forces?

 

[jbriggs444]

In a model where friction has constant magnitude, moving the feet from side to side will reduce the frictional force available in the fore and aft direction.

This is part of the secret to "doing doughnuts" in a parking lot.