Curious Magnets

Today I did the lab Curious Magnets with Louisa, trying to find and demonstrate how magnets transfer kinetic energy. In the first experiment, we taped four very strong square magnets every 2.5 inches on a ruler. Second on the right hand side, we put 2 silver magnetic balls, about half an inch in diameter, on the right side of each magnet, which stuck because of the magnetic force. Once the 9th ball got in the magnetic field, it was pulled toward the left side of the first magnet. This ball was traveling toward the magnet with 1 unit of kinetic energy, speeding up as it got closer causing the the first magnet to leave with a kinetic energy of 2 units because the potential energy was transformed into the kinetic energy. The last ball on the right of the first magnet left with 2 units, but speeding up and increasing to 3 units of kinetic energy as it reached the second magnet. The last ball on the right of the second magnet left with 3 units of kinetic energy, and the potential energy caused it to speed up to 4 units of kinetic energy by the first magnet. The last ball on the right of the fourth magnet left with 4 units of kinetic energy, but didn't speed up because there wasn't potential energy because there wasn't another magnet.




This is a picture of the effect of the first experiment, after we released the 9th magnet

The second experiment we did was to make a swinging pendulum using the Curie Effect. The Curie Effect states that when a magnet is heated up to 800 o F., it loses its magnetic power, causing the swinging magnet, a tiny neodymium iron boron magnet to be attracted to the larger, square magnet, but not stick, being repelled when it comes close, but pulled in while it is far away.

First, we made a twist of insulated wire with the tiny neodymium iron boron magnet attached to it.






Then we attached the two ends of the wire around the nail and lit the candle. The wire swung to and away from the larger magnet.




The completed second experiment

Motors: A Magnetic Movement

Today, Maya, Kayla, and I made motors with a straw, a battery, wire, safety pins, and straight pins. The first activity was to wrap 5 feet of wire around a 6 inch drinking straw. At the ends of the wire, we stripped of the coating, and attached that with tape to the positive and negative sides of the battery.



I stuck a pin at the edge of the straw, while the straw was horizontal. Because the straw with the wire wrapped around it is a potential magnet, and once it was attached to the batter, it was an electromagnet. That is why the straight pin when held next to the straw, it was attracted to the middle, where the magnetic field was strongest because that is where the wire was wrapped tightest.


Our second experiment was to make a motor that could turn a coil of wire around and around. Our first step was to wind the wire in a circle about an inch in diameter. Second, we attached the two ends of the wire to the inside of safety pins, which were open and attached with scotch tape to the positive and negative sides of the battery. Taped on top of the battery was a strong, but powerful magnet.

The coil was able to spin because as we the wire to the battery, we made an electromagnet. The electrons were moving inside the coil, each attracted to the magnet, then spinning.



This is a picture of our motor. The battery is right on top of the wire clippers, and the safety pins are on either side of the battery. The magnet is taped to the top of the battery.

BODY POWER

I was on school tours for this lab, so I decided to make it up at home because MM said I didn't need any special equipment. Basically, I did some math to find out what my caloric intake as an astronaut would be. We are going to use this in Mission to Mars, because we will be in the pod for four hours, and we will have to decide what foods we need to bring and eat.

First I calculated my Basic Energy Expenditure (BEE) with the equation BEE = 65.5 + 9.6(mass in kilograms) + 1.7(height in centimeters) - 4.7(age in years). My BEE, which means the number of calories my body uses throughout a day for metabolic purposes, was 1910 calories.

Second, I found my Resting Heart Rate (RHR) was 63 beats per minute. Then I found my Maximum Heart Rate (MHR), 144 beats per minute, with the equation MHR = 220 - age in years- RHR. From there I found my Working Heart Rate (WHR) by doing jumping jacks for two minutes, then measured my pulse for twenty seconds, then multiplied by three to get 140 beats per minute.

Next, I had to find what percent of my Maximum Heart Rate I was working at so I could find the number of calories I burned per minute. The percent was 53 %, which means I burned ~3.5 calories per minute dong jumping jacks.

Lastly, I found my Exercise Energy Expenditure (EEE) by multiplying the calories I burned per minute (3.5) by the number of minutes I would exercise (120). If I did jumping jacks for two hours, I would burn 420 calories. From that, I calculated my Daily Energy Expenditure (DEE), 2,330 calories per day, with the equation DEE = BEE + EEE.

So, If I exercise 2 hours a day, I burn about 2,330 calories per day. If I exercise 1 hour a day, I burn 2,120 calories per day. If I don't exercise at all, I burn 1910 calorie per day.

Power, Work, and Horsepower:

Power is measured by the amount of work you can do per second. And Horsepower is defined by the power a horse can steadily produce, I think now, and for this experiment, humans replace horses.

What I did to measure my work, was I ran up the stairs and timed myself from the moment my feet left the ground to the moment that they landed. I used this information in the equation Work = wight (in kilograms) x total height. Weight was determined as the force of gravity, so I had to use the equation F = M(40.5 kilograms) A(9.8 m/s^2) to find my weight. My work is 15,787. From there, I found my Power with he equation Power = work/time. My power was 2957.6 watts. Next I found my horsepower with the my work in watts/746 watts because 1 horsepower is equal to 746 Watts. My horsepower is 3.96.

So I can steadily produce 3.96 horsepower for a sustained period of time.

ELECTROMAGNETS

I actually was on school tours for the second lab, but I stayed after school, thanks to MM and Bert, and was able to make up the lab. (The other lab I missed for another school tout, I will make up over break because I can do it at home.) This was a hard lab to do without a partner because it involved holding things uprights on a dot as well as pushing the stop and start button to graph the magnetic field. What I had was a "magnetic field sensor", a computer interface, and the program logger pro to graph the magnetic field range.

First, I held the point of the nail to the top of the magnetic field sensor and graphed the magnetic field strength. Once I had this number established, I added coils of wire wrapped around the nail, with the other ends touching the positive/negative ends of the D battery. The magnetic field, theoretically will go up as you wrap more coils around the nail, and mine did, but it didn't jump as much as Bert or I expected.

Making and electromagnet is basically taking electricity (a battery) and a potential magnet (the nail). I ran electricity through the nail, causing it to become more magnetic. After I had done about 8 tests, the nail was magnetic enough for it to pick up a paper clip, although it didn't stay like that for a long time. And I think that the more winds around the nail you have, the larger the magnetic field because the coil generates a magnetic field when electricity is running through it.

Here is my data of the magnetic Field Strength per Number of winds:

Number of Winds Magnetic Field Strength
0 0.021
3 0.029
6 0.029
9 0.03
12 0.032
15 0.097
18* -1.104
21* -1.6

* This was when I changed the wires around and put the opposite ones on opposite sides of the batter, + or -.





I only got to Experiment 1, but over break, I will use this knowledge to build a speaker from the website Bert gave to us:

http://www.josepino.com/circuits/index.php?howto-speaker.jpc

IMPACT CRATERS

Today I did a lab with Emma S. and Lilly. The goal was to see how Gravitational Potential Energy and Kinetic Energy, affected the size of a crater, as well as width nad weight of the asteroid.

We had a box of flour about 1' by 1' with the flour spread about 5 inches deep. We dropped three different sized balls, each ball five times from 2 inches up, 4 inches up, 6 inches up, 8 inches up, and 10 inches up. The three different types of ball we used were ping-pong ball. a marble-like ball, and a golf ball.



Here, the marble, the golf ball, and the ping-pong ball are shown.
Dimensions of the balls:

Ping-Pong: 4 cm. in diameter and 3g. in weight
Marble-like: 2 1/2 cm. in diameter and 10g. in weight
Golf Ball: 4 cm. in diameter and 45g. in weight

These are the kinds of impact craters different balls made, just to give you a sense of how much the flour gave in:



Here are the tables of the sizes of the craters with different balls:







Ping-Pong:

Height Dropped From: Depth of Crater: Diameter of Crater:
2 inches 1 cm. 2 1/2 cm.
4 inches 1 1/4 cm. 3 cm.
6 inches 1 1/2 cm. 3 cm.
8 inches 1 3/4 cm. 3 cm.
10 inches 1 1/2 cm. 3 cm.

Marble-Like Ball:

Height Dropped From: Depth of Crater: Diameter of Crater:
2 inches 2 3/4 cm. 3 cm.
4 inches 2 1/8 cm. 3 1/4 cm.
6 inches 2 3/16 cm. 3 1/2 cm.
8 inches 2 1/2 cm. 3 3/4 cm.
10 inches 3 cm. 3 1/2 cm.

Golf Ball:

Height Dropped From: Depth of Crater: Diameter of Crater:
2 inches 2 1/2 cm. 4 cm.
4 inches 2 3/4 cm. 4 1/2 cm.
6 inches 3 1/4 cm. 4 cm.
8 inches 3 1/2 cm. 4 1/2 cm.
10 inches 3 3/4 cm. 4 3/4 cm.

Here are the (in order) marble-like ball, ping-pong ball, and golf ball height versus diameter of crater and depth of crater graphs. (I couldn't figure out how to change the color line, but for each graph, the line for the diameter is the one with higher y -numerical value):





Energy:

This it true for any object under these circumstances. Before the ball is dropped, as in it is being held in the air, it is all gravitational potential energy (GPE), and any time after that, until the very end, it is a mix of GPE and Kinetic Energy (KE), the sum adding up to the amount of Joules of the GPE at the top. At the split second before it hits the ground, the ball has all KE. GPE is converted into KE by the force of gravity.

When the ball hits the flour, it has all KE, and since KE is the energy of motion, it hits the flour with motion. I think that Newton's Third Law ties into this, "For every action there is an equal and opposite reaction" because as the ball hits the crater, the reaction is flour moving up around the ball causing a deeper crater. The craters are deeper when the ball is dropped from higher, because we know that GPE depends on the height, the higher it was dropped from, the more energy, both GPE and KE it will have. Because it has more energy, it will have larger velocity. When things have a large velocity, they will cause a bigger crater because there is they displace more. (I am a little confused). The diameter also has to do with the velocity at which the ball is landing, but also it just has to do with how wide the ball is. If the ball is dropped from just the right height, half the ball will be buried under the flour, which is the largest diameter you can have. (This is why the diameter on the graph goes up then down.)

I would like to do some kind of lab where we can measure the speed of the object, find the average, and use it to find the amount of GPE and KE the ball has.

HEAT SHIELD

The is our second trial design. Amalia and Anna made this which was a spherical piece of tin foil wrapped around the metal part of the stick. This design didn't work very well because the the tin foil was touching the metal, so when the metal got hot the hot glue melted. This picture was taken after the test, so the tin foil is a little bit burned.



This is our third design in its test. This on worked very well, withstanding the heat 3 minutes and 10 seconds, double that of the two previous trials. This design worked well because the tin foil and the mesh wasn't touching, and neither of those were touching the metal stick. This shield protected the glue without touching it rather than protecting it while touching it, causing the heat to spread.



This was the burning of my heat shield. It lasted 1 minute and 31 seconds before the hot glue melted and it fell off. This design didn't work very well because everything was touching the metal and/or the glue so the heat spread pretty quickly.



This was my design of a heat shield where I put everything in layers on the metal part of the stick. First the nut, the tin foil, the mesh, and then the washer. This design didn't work because all of the shield was touching the hot glue and not protecting the metal part of the stick, so the metal heated up and the heat spread quickly.


Today Anna, Amalia, and I designed a heat shield out of a 5" by 5" piece of mesh, a
5" by 5" piece of tin foil, a washer, and a nut that could withstand heat from a propane torch.

1st Trial: This was the one that I made. Everything was stacked on top of each other so it didn't work very well. It lasted 1:30 minutes.

2nd Trial: Anna and Amalia made this one. It also didn't work very well because everything was touching and there was only one layer of foil; they didn't fold it over. It lasted 1:35 minutes.

3rd Trial: We all made this one together. We decided that for the metal of the stick to stay cold, we would have to make it so the back-up piece of shield (the mesh) could be the only thing touching the hot glue/metal. We also decided that the tin foil couldn't be touching the mesh, otherwise when the foil got hot, it would spread quickly. So we made a cup shaped piece of foil and attached it with a little corner to the mesh. This design worked very well, and the hot glue melted after 3:10 minutes.

Relation to the Transformation of Energy:

There are 3 types of energy in this experiment:

Convection: The transfer of energy by the actual movement of warmed matter

Conduction: The transfer of energy through matter from particle to particle

Radiation: Electromagnetic waves that actually transport heat through space


The heat from the torch is primarily radiation. The radiated heat travels in waves through the air to the shield. Once the heat is at the shield, the energy is primarily conduction because the heat is moved particle to particle along the metal. To prevent damage, the shield has to absorb the heat and conduct it away from the sensitive structures behind it. Because of the first law of thermodynamics (energy can not be created or destroyed), after some time the shield is going to get really hot and probably burn up. When astronauts are coming through the atmosphere back to earth, their heat shields heats up so much that they glow red hot.

At first, we though that the heat shield was just to block the heat, not to conduct it away. That is the reason that our first designs didn't work; we had everything connected to the hot glue. We though that the tin foil would just block the heat, not conduct it. What happened in the first two trials was that the heat from the torch made the foil warm, which spread to the mes, which spread to the metal, which melted the hot glue because everything was connected. Our last trial worked because the tin foil conducted the heat away from the metal, while not touching the hot glue.

GEOMETRIC SKETCH PAD

This is a sine graph, tweaking the simple sin(x) bu multiplying and adding/subtracting in and outside the equation to magnify it more, or shift the y-intercept around.