Physics Blog 6: Collisions

I was thinking about collisions in real life when I saw the perfect topic for my blog on TV: the Texans vs. Titans game! I was going to go find some footage of tackling in football when Cortland Finnegan and Andre Johnson provided me with all the footage I needed:

Collisions

When the punching starts, Andre Johnson's fist clearly has more momentum than Cortland Finnegan's face, as Finnegan's head bounces back every time Johnson strikes him. This means that, since the equation for momentum is p=mv, Johnson's fist has either greater mass or greater velocity - in this case, it is less massive than Finnegan's head and therefore must have far greater velocity. Additionally, both players exert enough force to overcome the friction between each other's heads and helmets and tear the helmets off at the onset of the fight. It's exciting to see physics concepts at work!! :)

Physics Blog 5: Picture Poses

This past week was Homecoming, and there were probably hundreds of possible topics for blogs. However, I really noticed physics at work when we were taking a group picture:

You can see on the right hand side that my friends Val and Andrew and I were holding Kevin motionless in the air. To achieve this, we had to offset his weight with the force we were applying from beneath him, and since he was not touching the ground, our three forces combined had to equal what the normal force would have been. If you look at other people in the picture, you can see other examples of the normal force being replaced with an equal force. PHYSICS IS FUN!! :)