Hey, nothing better than being told you can roll things into each other, right? Unless your me and accidentally cause the funniest moment of the class when you discover that there springs on each of the cars that can be pushed in and hidden and popped out at the press of a button. ;)
This lab was all elastic and inelastic collisions, with equal and different weights. We did 16 total tests, 8 inelastic. For the elastic "collisions" there were magnets in the carts facing each other. Opposite charges came together so the carts bounced away as they got close. For the inelastic tests, velco, so that the carts would lock.
So lets just establish right now. Whenever heavy cart met light car (the heavy cart would have a mass three times more than the light cart) heavy cart won, and it often resultd in light cart going flying the other direction, unless it was going the same direction as the heavy cart, in which case their momentum would end up becoming one between the two of them.
When the carts were the same mass, they would exchange their momentum which was much closer to the same. When the exchange happened between heavy cart and light cart, one cart almost always slowed dramatically.
Friday, April 29, 2016
Circly, Mathy stuff!
Well, this was another one I wasn't expecting. Spending a class analyzing circles. And then reporting out findings on a slope of a graph involving Diameter vs. Circumference. All done by hand. This meant measuring around the outside of each object for the circumference, using tools to measure the diameter, and outlining the object on a grid to then attempt to calculate area.
After the calculating, it was time to go to the infamous whiteboards, to create a graph with one set of data. We may have had an outlier on that graph, but then again, we may have also cheated when it came to getting data for a hula hoop because that was going to be a nightmare to measure. So it was to the internet for the hula hoop data. But using the data we got for diameter and circumference, we were able to make a graph with a slope based on 6 items we measured and the hula hoop.
After the calculating, it was time to go to the infamous whiteboards, to create a graph with one set of data. We may have had an outlier on that graph, but then again, we may have also cheated when it came to getting data for a hula hoop because that was going to be a nightmare to measure. So it was to the internet for the hula hoop data. But using the data we got for diameter and circumference, we were able to make a graph with a slope based on 6 items we measured and the hula hoop.
Thursday, April 28, 2016
Cartoons are real...they just use fake physics.
Ok, I can honestly say, when I signed up for physics class, I never imagined that part of the class would be cartoons. Like, really? I am going to go to class to...watch cartoons??? But there is more to it than that. We must laugh at the comedy show that is cartoon physics. Unless of course a coyote can push a boulder which appears to be more than twice the size of himself down a ledge, across a road, back of a cliff on the other side which is taller than the ledge, and when all is said and done, have a boulder on top of himself.
Once again, laugh away at the cartoon physics because that shouldn't be physically possible. But it does make an interesting conversation, and lead to a lab involving attempting to figure out just how high you would need to release a ball from to get it to go in a loop, where you then use mgh=PE to figure out the potential energy needed to create such a phenomena.
But lets look for a moment at the energy. The boulder starts with all potential energy, and ends with all potential energy once it lands on top of the coyote. But at the base of the canyon it would be all kinetic energy, since there is no way it can gain any more energy (and yet it magically does) and as the boulder goes up the cliff and is in the air, it has both.
Back to our experiment. Based on what the cartoon showed, you should be able to release a ball at half the height of something and have it go in a loop. That is illogical though, because the object needs to have enough energy to go up the other side. So we did a mini version of this to see what the minimum height to get a ball to go in a loop would be. We got our ball to go around at a height of 14in. or ..228m in extra height, with the ball weighing 9.2g. mgh=PE made PE=20.5564
Once again, laugh away at the cartoon physics because that shouldn't be physically possible. But it does make an interesting conversation, and lead to a lab involving attempting to figure out just how high you would need to release a ball from to get it to go in a loop, where you then use mgh=PE to figure out the potential energy needed to create such a phenomena.
But lets look for a moment at the energy. The boulder starts with all potential energy, and ends with all potential energy once it lands on top of the coyote. But at the base of the canyon it would be all kinetic energy, since there is no way it can gain any more energy (and yet it magically does) and as the boulder goes up the cliff and is in the air, it has both.
Back to our experiment. Based on what the cartoon showed, you should be able to release a ball at half the height of something and have it go in a loop. That is illogical though, because the object needs to have enough energy to go up the other side. So we did a mini version of this to see what the minimum height to get a ball to go in a loop would be. We got our ball to go around at a height of 14in. or ..228m in extra height, with the ball weighing 9.2g. mgh=PE made PE=20.5564
Why must there be unbalanced forces!?! We don't need to move in our lifetimes!
What are unbalanced forces. Well, a person skydiving is an unbalanced force. That is, the force of gravity is acting straight down on them, but nothing is acting up so they are plummeting down towards earth. The forces acting on that person are unbalanced.
In other words, balanced forces = equilibrium = stationary objects, unbalanced forces = some form of motion as the balances are unable to keep each other in check.
In other words, balanced forces = equilibrium = stationary objects, unbalanced forces = some form of motion as the balances are unable to keep each other in check.
One small step for mankind, one large...crash??? For eggmanity???
Yeah, not my finest work. Stay up late and wake up early designing a parachute, just to release it wrong and have the chute not open. But even though the design had a fatal flaw in that if the chute didn't start open it wouldn't open, the work that went into the multiple designs was there.
It also doesn't ignore the fact that since I didn't get the air resistance I needed to create a nice, relaxing flight for my egg, my parachute accelerated all the way to the bitter end. That left me wishing I had gotten a video of the failed flight for two reasons.
1) There is nothing like watching an egg smash against the floor of the school and not getting in trouble for it and;
2) I could have looked at the video more closely and figured out how fast my egg plummeted to the ground at by calculating how long it took, how heavy it was, and breaking that down into chunks (m/s/s).
Now if only I hadn't had my little mini-chute. Then it really would have fell in a hurry.
Anyways, I mentioned 3 designs. Well, I have already referenced my initial design. My "mini-chute." A cute little chute that probably couldn't hold my than a couple cherry tomatoes, just because it didn't have enough surface area. So I moved to my second design. A larger square parachute. The problem with this, it there was no real way to make it stay open and not fold in on itself. So I went to pan three (all made up as I went). My little mini-chute underneath a mushroom-top larger parachute. This design showed some promise and I was running out of time and materials, so I decided that I would except design #3 as my final test design.
Needless to say, it didn't go as I hoped. But the experimental design phase was there, and it was as thought out as can be for 1am and 5am. :)
It also doesn't ignore the fact that since I didn't get the air resistance I needed to create a nice, relaxing flight for my egg, my parachute accelerated all the way to the bitter end. That left me wishing I had gotten a video of the failed flight for two reasons.
1) There is nothing like watching an egg smash against the floor of the school and not getting in trouble for it and;
2) I could have looked at the video more closely and figured out how fast my egg plummeted to the ground at by calculating how long it took, how heavy it was, and breaking that down into chunks (m/s/s).
Now if only I hadn't had my little mini-chute. Then it really would have fell in a hurry.
Anyways, I mentioned 3 designs. Well, I have already referenced my initial design. My "mini-chute." A cute little chute that probably couldn't hold my than a couple cherry tomatoes, just because it didn't have enough surface area. So I moved to my second design. A larger square parachute. The problem with this, it there was no real way to make it stay open and not fold in on itself. So I went to pan three (all made up as I went). My little mini-chute underneath a mushroom-top larger parachute. This design showed some promise and I was running out of time and materials, so I decided that I would except design #3 as my final test design.
Needless to say, it didn't go as I hoped. But the experimental design phase was there, and it was as thought out as can be for 1am and 5am. :)
Force diagrams, Balanced Force and equilibrium? Same difference
So in my last post I explained balanced force as anything that had equal forces so that it wasn't moving. That can be called being in a state of equilibrium.
So take this for an example. You place an apple on the table and it stays perfectly still. First off, what forces are acting on the apple? The table is acting straight up, and the force of gravity is acting straight down. You can draw that out to be a force diagram. That is a diagram which is used to visually represent every force that is acting on an object.
But back to the apple, it is perfectly still. That means that to force put on the apple by the table and the force put on the apple by gravity are equal. That apple is in a state of equilibrium. This literally means that it is balanced.
So take this for an example. You place an apple on the table and it stays perfectly still. First off, what forces are acting on the apple? The table is acting straight up, and the force of gravity is acting straight down. You can draw that out to be a force diagram. That is a diagram which is used to visually represent every force that is acting on an object.
But back to the apple, it is perfectly still. That means that to force put on the apple by the table and the force put on the apple by gravity are equal. That apple is in a state of equilibrium. This literally means that it is balanced.
Balanced forces make my life easy. Thank you Newton
Life is full of forces. The force of gravity, the force of momentum, the force of friction. But one thing is very simple. For every action there is an equal and opposite reaction. This is one of Issac Newtons three laws, and the reason your car slowly comes to a stop while you don't press on the gas or break. Because when no extra forces are acting, the car will become a balanced force. This means that it isn't doing anything, because the force it is putting out is equal to the force being put on it.
Try this. Put you hand on a countertop. Does it move? Probably not, right? That is because the force being put on the countertop is being equaled by other means, in this case probably supports underneath it. So the force you are putting on it is being balanced. Balanced forces.
Try this. Put you hand on a countertop. Does it move? Probably not, right? That is because the force being put on the countertop is being equaled by other means, in this case probably supports underneath it. So the force you are putting on it is being balanced. Balanced forces.
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