Because no net force equals no movement, you provide a pushing force, such as a hit with a hockey stick, which causes the puck to travel at a constant speed indefinitely. As it approaches the goal line, the player applying the push decreases the force he or she is providing, causing the puck to decelerate and eventually stop. Ice hockey is a game of collisions. When players shoot at the puck they are trying to hit it; when players are checked they are often weighing down the ice in pursuit of the puck. In addition, there are shots where no contact is made with the puck, such as when a player shoots high into the air. All of these events cause the players to move relative to each other, which is what makes up gameplay on the ice. There are two types of forces that act on the puck while it is in play: linear and angular. Linear force is pressure applied along a straight path, such as when a player hits the puck with his or her body. Angular force is torque applied around a point not on the path of the force, such as when a player spins around on one foot in order to fire a shot. When a player pushes the puck, they are applying linear force.