How Physics Applies at the BEACH

We always talk about how we can use physics in our daily lives, but how can we continue to recognize what we've learned this year throughout the summer? Here are 10 ways:

#1

Let's say you are lugging your a cart to the beach and in it is your beach ball.  When you hit a bump in the road, the ball is thrown into the air.  However, it doesn't fall out of the cart, but travels with it. Why is this?
Newton's law explains inertia, stating that an object in motion will stay at motion and an object at rest will stay at rest unless acted upon by an outside force.
As you pull the cart, the cart has a certain velocity.  Because the ball is contained in the cart, it is moving with the same velocity as the cart.  Since no force is stopping the ball, it will continue to move with the cart, therefore land back in the cart

#2

Let's say you and your friends decide to jump off the cliff at the beach
However, you don'y want to land on the rocks below.
You can use Physics to calculate where you will land:

Projectile throwing is much like free fall straight down, however, one must take the horizontal velocity into account as well as the vertical.  Finding horizontal velocity is easier because it stays constant (due to Newton's first law).

If given the distance (d) in the graph shown above, you can use the  (d = 1/2(10)t²) equation to solve for the time (t).  Once you know the time, you can use the (v=d/t) equation to find the distance, and make sure you won't land on the rocks!  

#3

As you go to the beach each day, you notice the the tide changing.  Here's how you can impress your friends by explaining why this happens: 

The Earth's natural tides can be explained through the pulls of gravity and Newton's 3rd Law.

Each day there are 4 tides in total:

• 2 high tides
• 2 low tides

You can explain these tides through Newton's 3rd Law.

Notice how, in the image below, the distance A is lesser than the distance B.

Because the distances are different, point A and point B will experience different forces from the moon's pull.

We know that Force and Distance are inversely proportional.

Therefore, 

• Since B has a greater distance, the force will be lesser,
• And since A has a lesser distance, the force will be greater.

This DIFFERENCE IN FORCE causes the water surrounding Earth to create an oval:

And depending on where you are located on the Earth's surface, you will experience a low tide or a high tide

#4

When you think you have these tides all figured out, you notice high tides are sometimes higher, and low tides are sometimes lower than usual.

You can explain this through physics too:

There is also a pull between the Earth and the Sun.  As the distance between the sun and Earth changes throughout the year, this pull has more or less effect.  (Less drastic than the moon however, but still noticeable)

This is why we have Spring and Neap Tides:

#5

You and your friends go to the carnival on the beach.  Jasmin decides to climb toward the ceter of the ferris wheel because she wants to go faster but you know this will not work.  Physics can explain why...

Jasmin and Princess will experience the same number of rotations, however, Princess will have to go faster (have a greater tangential speed) to reach them.  This is because her radial distance is greater.

v ~ r w

(tangential velocity ~ radial distance * rotational velocity)

Since Jasmin decreased her radial distance, she therefore decreased her tangential speed as well.  Therefore, she will go slower than us.

#6

You decide to pack some strawberries for a snack at the beach. So, you cut up strawberries to put in a ceramic bowl and put plastic wrap to cover them. This plastic wrap doesn’t just magically stick to the bowl. Thanks to physics we know why exactly, the plastic wrap sticks to the bowl. 

The plastic wrap is charged by friction and when brought near the bowl, the bowl polarizes. The positive charges in the bowl move close to the negative plastic wrap and the negative charges in the bowl move away from the plastic wrap. The distance between the opposite attractive chargers is smaller than the distance between the like repelling charges. Coulomb’s law states that the force between any two charges are inversely proportional to the distance. F=kq1q2/d^2. Because there is a greater distance between the repulsive forces, the forces between them will be less than closer attractive forces. Therefore, the plastic sticks to the ceramic bowl.

#7

You carry your fruit in a basket to the beach. Although this may feel challenging and it may feel like you are doing a lot of work, however, in physics terms, you are actually doing NO work. The force, which is the basket, being pulled down by gravity is not parallel to the horizontal distance the cooler is moving. Work is the effort exerted on something that will change its energy. 

         Work = Force * Distance
One important thing to remember is that in order to calculate work, the force and distanceMUST BE PARALLEL 

Therefore, you only do work when you lift the basket, but not in carrying it across the beach.

#8

While you're at the beach, a lightning storm rolls in.  Where did this lightning come from?  Physics can explain that...

The movement of particles in the clouds causes friction which causes the cloud to polarize. Because the electrons move to the bottom of the cloud, the positrons from the ground become attracted to the cloud, therefore polarizing the ground as well. The cloud and ground want to equalize, so once the pull builds to a certain point, an electric shock will transfer charge to equalize them, which we see as lightning

#9

It's so hot at the beach that you go home and stand in front of the fan.  You wonder how this fan spins.

  This is because inside the fan is a motor.  Motors convert electrical energy (from the wall socket) into mechanical energy that causes the fan blades to spin.  In a motor, a current runs through a coil, which feels a force because it is within a magnetic field. It feels this force because it is MOVING and all moving charges feel a force in a magnetic field. The force felt by the wire causes a torque, causing the coil to spin.  This spin produces usable mechanical energy.

#10

While you and your friends take a walk on the beach at night, you wonder why you've never seen the Northern Lights.  

Physics explains thy the Northern Lights only happen at the poles:

Cosmic rays released from outer space are directed toward the Earth's equator.  However, once the rays come into contact with Earth's magnetic fields, they spin and follow the fields all the way to the poles, where they create waves of light.  This is helpful to our health because cosmic rays can be very dangerous to our health, but sadly, we can't see the unless we travel to the poles.

YAY PHYSIX!!!?