Top Ten Physics Examples in Sports

1.) Lets say you are skateboarding around your neighborhood. When you stop to take a rest your friend comes up to you and pushes your skateboard. To your surprise you fall exactly where you were previously standing on your skateboard while your skateboard rolls about 20 feet away. The reason why this occurs is because of Newtons first law which states that an object in motion stays in motion and an object at rest stays at rest unless acted upon my an outside force. Because you were initially at rest your body tends to stay at rest even after your friend pushes your skateboard.

2.) In professional skydiving, divers have to take into consideration their acceleration, speed, and air resistance. The skydivers acceleration is at its greatest when they first jump out of the plane (acceleration = net force/mass). As the person falls their force of air resistance increases. The equation used to solve for the divers net force is F weight minus F air. As F air increases F net decreases, and once the F net reaches zero the diver is in a state called terminal velocity, meaning that they are moving at constant velocity.

3.) In baseball say a ball was hit at a 45 degree angle and is moving 20m/s in the horizontal direction and 40m/s in the vertical direction. If you wanted to calculate how far away the ball will land you would use the physics equation distance = velocity x time (d=vt). Since we know the speed in the vertical direction we can calculate how long the ball will be in the air. 

Now that we know the ball will be in the air for 8 seconds we can plug it into the equation d=vt (note that the velocity used in this equation will be the horizontal velocity no the vertical). 

d = (20)(8), the ball will travel 160 meters.

4.) Lets say you are in a sail boat race, and you are trying to get to the other side of the river as fast as possible so that you can beat your opponent. The fastest way to travel across the river would be to paddle in the diagonal direction up stream so that your boat moves straight across. The reason why this works is because of vectors which show direction and magnitude. Here is an image I made for clarification.

5.) Surfers who like to practice when the waves are the biggest need to take into account how high and low tides work. Physics is used when figuring out when hight and low tide is, for it has to do with the force from the moon and they are also caused from the difference in force from either side of the earth. In this image both sides A and B are experiencing the same force and are both in high tide due to the positioning of the earth.

There are two types of tides, and they are spring tides and neap tides. Here is what they look like:

Highest of high tides and lowest of low tides occur when there is a full or new moon (Spring tides). Ideally the best time to go surfing is when there it is high tide. Each day there are 2 high tides and 2 low tides meaning that every 6 hours they alternate.

6.) Why do wrestlers keep their legs shoulder width vs. feet together? There is physics in why they does so, because when a wrestler opens up their stance they are widening their base of support. The wider their base is the more support they have making it harder for someone to push them over. Pretending that the rectangles are humans, you can easily see that the first person is more likely to fall over because they have a smaller base of support.

7.) When performing the triple dive in professional diving, there is physics behind why divers extend their arms and legs after spinning. When a diver opens up their arms and legs their rotational velocity decreases, because they are putting more mass away from their rotational axis. This gives the diver more rotational inertia. By doing this they stop their spinning motion allowing themselves to dive into the pool with minimal splash.

8.) In race car driving, members need to take into account the physics concept of centripetal force which means center seeking force. When the race car rounds a corner at top speed the friction between the tires and the road provides a centripetal force that keeps the car on the road. The person who is in the car will feel a force towards the center of the curvature, and the name for it is centripetal force.

9.) Physics can be seen in gymnastics, for it explains why it is safer for gymnasts to practice on soft surfaces rather than on the concrete.  The reason why is because no matter what they land on they are going from moving to not moving, therefore the change in momentum is the same regardless of how they are stopped 

p=mv

∆p = p final - p initial

Because the change in momentum is the same regardless of how the person is stopped, the impulse is also the same regardless of how quickly you are stopped.

∆p = J

J= F x ∆t

It would be foolish of the gymnists to practice on concrete because since the impulse is the same the force they will experience when they land will be greater and the change in time will be smaller. While if the gymnast practices on softer surface their force will be smaller because the softer surface increases their stopping time. And less force means less injury.

10.) Physics can be seen while biking, for the concept of torque is applied to the bike pedals which cause it to move. The metal shaft that lies perpendicular to direction in which you push down on the pedal is the lever arm (torque =  force x lever arm). Force and lever arm are inversely proportional meaning if you increase the pedals lever arm you use less force and vis versa. The biker can use torque to measure how much force is acting on the pedal causing it to rotate.