Slide 1
Hey everybody my name is Alejandro Ferreira and today we will be investigating the physics
behind a pitch in baseball.
Slide 2
Introduction
A pitch is the act of throwing a baseball toward home plate with the intention’s of getting the
batter out. There are many different pitches in the sport, but today we will be analyzing the
physics behind a fastball. A fastball is a fundamental pitch in baseball that every pitcher must
know.​
Slide 3
The video example is Nate Pearson pitching a 100mph fastball for a strikeout. The video
displays the physics of a fastball in full effect which I will explain later on.
Slide 4
Forces Used On A Fastball
After leaving a pitcher’s hand, a fastball is influenced by 5 forces: gravity, drag, applied
force, normal force and net force. Gravity pulls the ball downwards, drag slows the ball
down, applied force as the pitcher pushes the ball forward, normal force which is opposite of
gravity which cancels out, and net force which is the sum of the forces which can be
calculated by adding all the forces together or by using the formula Fnet =ma.
Slide 5
Formulas
The formula for gravity is Fg=mg (acceleration due to gravity= -9.8m/s²) , I previously stated
that the formula for net force is Fnet= sum of the forces or Fnet = ma, the formula to find the
mass of an object is m = Fnet/a and acceleration can be found using the formula a= Fnet/m
or (Vf-Vi)/(tf-ti).
Slide 6
Calculations
The calculations for the force of gravity is Fg=0.148835kg ✕ -9.8m/s² which gives you
-1.45N. The calculations for acceleration are a= (44.704-0)/(0.4-0) which gives you
111.76m/s²​. The calculations for net force are Fnet= 0.148835kg ✕ 111.76m/s² which gives
you 16.3N.
Slide 7
Projectile Motion
The motion of a projectile under gravity is called projectile motion.​The projectile motion of a
fastball is a parabola that reaches its maximum height while it is still in the hand of the
pitcher and then once it is released it steadily decreases until it hits the glove of the catcher at
the knees of the batter. The approximate angle that the fastball declines at is 40 degrees. The
formulas and calculations that you see are to aid you in finding the maximum height, time of
flight, and the horizontal range. In this scenario the initial velocity would always be 0
because at a time of 0 seconds the ball is not moving is not moving.
Slide 8
Newton's Second Law
According to Newton's second law, the acceleration of an object caused by a net force is
directly proportional to the magnitude of the net force, in the same direction as the net force,
and inversely proportional to the mass of the object. The acceleration of an object increases in
proportion to the force acting on it. The acceleration of an object decreases as the mass of the
object increases.​The image to the right sums it up quite well stating that if you apply more
force to an object it accelerates at a higher rate, but when the mass of the object increases, the
force that you are putting on it will begin to do less work and the acceleration will begin to
decrease . This relates to pitching in baseball because the more force that you put into your
throw, the higher the rate of acceleration will be.
Slide 9
Newton’s Third Law
Newton's third law of motion states that each action force has a reaction force that is equal in
magnitude and opposite in direction. An example of Newton's third law of motion would be
when a baseball makes contact with a bat because in that moment it is a prime example of a
equal but opposite reaction since the bat is using equal force against the ball.​
Slide 10
Sound
In baseball, you are able to hear the sound of the wind as the baseball travels through the air.
Not only can you hear the wind, but you can hear the sound of the baseball reaching its final
destination which is the glove of the catcher. The sound is more distinct when you are
listening to a high velocity pitchers such as Nate Pearson, Luis Severino and Gerrit Cole who
can basically hit 100mph with their fastballs when they are at full strength.​
Slide 11
Connection to real life
We use forces, projectile motion, Newton's second law, Newton's third law, sound. We
experience the force of gravity every day because if we did not, we would be floating in the
air. For example, when we jump, we immediately go back down. Normal force is the force
acting against gravity but since it is equal to gravity at 9.8m/s². We experience this all the
time, for example, when we are walking. An example of friction is when we rub our hands
together or when we shuffle our feet on a carpet. We use projectile motion all the time
especially when we play sports like basketball, soccer, and football. We use projectile motion
when we shoot a basketball, kick a soccer ball or throw a football. Newton's second law is
applied when we are travelling because when we pull a carry-on bag it is quite light, and we
are able to move faster, but with a heavier suitcase your acceleration will decrease. We use
newton's third law when we put textbooks on a desk. The textbooks are the action force since
they are pushing down on the desk, and the table applies a force on the book going upward
(normal force). We use sound when we put our headphones on to listen to music.​
Slide 12
Summary
In conclusion, today we learned that a fastball uses 4 forces, drag, gravity, normal force and net
force, we also learned that a fastball uses projectile motion, Newton's second law, Newton's third
law, and sound​