Newton's First Law of Motion: An object in motion tends to stay in motion until acted upon by an outside force.
This is the basis of many elements of softball.
When the pitcher throws the ball, it travels in the direction of the release point. The ball continues on the path until the batter hits the ball, changing its direction and speed.
The key to getting a good hit in Softball is to hit the ball in the "sweet spot" of the bat.
"Sweet Spot" - The point at which there is minimal vibration from contact with the ball, thus maximizing the energy transfer and distance that the ball travels. It is located about 17cm from the end of the barrel.
You can tell when you've hit the ball at this spot because it minimizes the sting you feel in your hands (which is really nice especially if you're in Alaska and everything's cold)
By the physics analysis of hitting a ball, if you hit it in the sweet spot, the reaction force is always equal to zero no matter how hard you hit it.
(The Physics of Hitting a Baseball)
Now, when you are hitting a ball, there are a couple of forces to examine.
There's the force of gravity acting down, the normal force acting up, the frictional force of your feet and the ground, the applied force given by your swing, and the force due to air resistance.
The Applied Force by the batter on the ball makes the ball travel in the opposite direction at a different speed.
The ball is going at a constant momentum until it makes contact with the bat. The forces on both objects are equal and opposite (according to Newton's Third Law). The force of the bat on the ball make the ball speed up and change direction and make the bat slow down.
The ball experiences a greater acceleration because its mass is smaller.
The force between the bat and the ball isn't constant.
And the force is very large, changing the balls direction and speed.
The force is noted in a parabola shape.
Newton's Second Law can help us calculate the average force put on the ball by the bat:
Favg = mvf-mvi/(delta t),
where m=mass, vf=final velocity, vi=initial velocity, delta t=change in time
The average contact time between the bat and the ball is 0.7 milliseconds.
The graph starts and ends at zero and has a maximum approximately at the center, t/2 of the time of contact.
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