Sunday, November 8, 2015

The Lacrosse Style Hockey Goal

Since recently we have been learning about rotation, that is what I focused on when looking at the physics of hockey. Hockey has quite a lot of physics involved but I am only going to be focusing on the physics of the lacrosse style goal in hockey. This type of goal occurs when a player moves his stick at such a high velocity that he is able to scoop the puck off the ice and throw it into the goal, like one does in lacrosse, hence the name.
To do this the player must first flip the puck on its side so it has contact with the whole blade of the stick. Then the player guide the puck in a curved trajectory causing the puck to feel centripetal force and experience centripetal acceleration. For this to work, the velocity must be fast enough that the centripetal force pushing the puck against the stick is enough to overcome the force of gravity. The friction between the puck and stick must be sufficient enough that the puck will not fall.
                To calculate how much speed a player would need to do this I am going to estimate the the coefficient of friction between the puck and the stick to be 0.2. The mass of the average hockey puck is 163 g. Finally the average height of an NHL player is 6’ 2” (1.8876 m) and the average player has a stick that goes to the height of his nose, which I will estimate is halfway down the face. The average male face is 21.8cm tall, so the average stick height will be estimated to be 1.7786 m (the average height of a player, subtracted by half the length of the average male face). This is what I will assume to be the radius. 


FFR=mg
µFN=mg
(0.2)FN=(0.163)(9.8)
FN=7.897 N
FN=(mv2)/r
7.987=(0.163v2)/1.7786
V=9.34 m/s

As a reference the average speed of a player is 12.5 m/s.

No comments:

Post a Comment