Blog 4: Playing smart with friction

Our most recent lessons on friction gave me a better understanding of an experience my friends and I had with water slides. The last Sunday before school started, me and a couple of friends took some boogie boards and surfed down a tarp ramp. One of my friends tried to slide down with out a board and before we added water. The coefficient of friction between his skin and the tarp was high, making it hard for him to move. To decrease the coefficient of water we got a bucket of soap water and poured it down the ramp creating a slick path. I was able to slide down easily because the coefficient of friction between my board and the water was pretty low. I started at rest, and my friend's push overcame the static friction force accelerating me down the tarp.

Physics has really improved my view on daily activities. To most its common sense that water will make us go faster but we never question why. I don't have enough information to actually solve for my friends force, friction, or acceleration, but if given some values (perhaps the angle of the ramp) you could go about solving for different variables using the following equations found from interpreting a Free Body Diagram of the scenario.

BLOG 3: Inertia

This weekend I got my whole family to attempt the tablecloth trick. It took my dad 4 tries, but the girls in the family got it their first try :) Ironic because dad is the phyics master in the family, always helping my sister and I with our homework. I think he didn't get it the first time because he was applying too much of an upward force versus a slight downward pull.

The famous tablecloth trick is possible and can be explained using Newton's First Law of Motion: objects at rest want to stay at rest unless and outside force acts upon them. If you pull the tablecloth fast enough it will slide right out because the friction force between the cloth and the dishes is not strong enough to pull the dishes with it. Unless the force is strong enough to overcome the dishes inertia, they will remain at rest on the table.