Physics of Hockey — The Slapshot

In the slapshot, players can clock puck speeds of over 100 miles per hour, making it the hardest shot in hockey.

The hockey player begins the slap shot by raising the stick behind his body, as shown below.

http://en.wikipedia.org/wiki/Slapshot

Next, the player violently strikes the ice slightly behind the puck, and uses his weight to bend the stick, storing energy in it like a spring. When the face of the blade strikes the puck the player rotates his wrists and shifts his weight in order to release this stored energy and transfer it to the puck. The result is the puck reaching a speed faster than it would if the player simply hit the puck directly. The kinetic energy of the puck after impact is equal to the stored energy in the hockey stick.

The figure below shows the point of impact between the stick and puck. You can clearly see the bend in the stick.

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The physics of hockey taking place here is the transfer of energy from player to stick, and from stick to puck. The advantage of storing energy in the stick is that (upon release) it strikes the puck faster than the player can, causing the puck to reach a greater speed.

The player applies a force to the hockey stick. The friction between the stick and ice forces the stick to bend and create potential energy. The player transfers weight from their back leg to their front leg to put more force on the flex of the stick. The blade of the stick is up in the air at the end of the shot to push the puck up against gravity. When the potential energy is released, the stick snaps back and transfers its energy to the puck. The stiffer the flex the more potential energy, when flexed, The puck shot in the air will have a curved path coming back to the ice due to gravity. The puck accelerates in the direction that the sticks force is applied on it (Newton’s 2nd Law) the player puts all their weight on their back leg and raises their stick above their head creating potential energy. The type of stick used has a big impact on how hard a shot will come off. Composite sticks will have a better flex which means more potential energy with having a less chance of the stick snapping. Acceleration of the puck is determined by how much force is applied to the stick.