The equation for calculating average force is force = mass x acceleration.
The mass of the puck can be calculated by using its weight and the acceleration due to gravity. The equation is mass = weight/acceleration due to gravity.
The acceleration of the puck can be calculated by using the equation acceleration = change in velocity/time. In this case, the change in velocity is 59m/s and the time is 0.0021s, so the acceleration is 28,095 m/s^2.
The stopping distance of the puck can be calculated by using the equation distance = initial velocity x time + 1/2 x acceleration x time^2. In this case, the initial velocity is 59m/s and the time is 0.0021s, so the stopping distance is approximately 0.123m.
The average force exerted by the goalie on the puck can be calculated by using the equation force = mass x acceleration. In this case, the mass of the puck is needed to calculate the force. If we assume the mass of the puck is 0.17kg, then the average force exerted by the goalie on the puck is approximately 4,776 Newtons.