Here we are! Look below:
SPEED OF CAR AND PLACE IT CAME IN:
Our car, VELVET, went further than 5 meters, approximately 8 or 9 meters.
When we did the official trial, Mr. Rue timed our car to go the 5m in 2.84 seconds!!
The speed of Velvet can be calculated by using the simple formula: distance/time.
~ Distance/Time
~ 5m/2.84s = 1.761 meters per second.
Out of everyone's official times, (of all 3 class sections), Velvet was the 2nd fastest. Of my class, A-block, it was the fastest. Good job, Velvet.
PHYSICS OF THE MOUSETRAP CAR:
A.)
- Newton's 1st Law: The more mass an object has, the more inertia it has. Velvet was fairly lightweight, so it was easier (less resistance) for the car to start moving.
- Newton's 2nd Law: Acceleration = Fnet/Mass. The lesser the mass, the more it accelerates. Velvet had a small mass, so it had a greater acceleration at the start!
- Newton's 3rd Law: Every action has an equal and opposite reaction. As the CDs were in contact with the ground, the relationship reminded me of the "horse and buggy" topic. The CDs had friction wight he ground, so it allowed for the car to actually move forward.
B.)
- The static friction between the bottle cap axles and the fuzzy hangers: the car has resistance on the axles and body to start rotating while currently at rest.
- The other is the kinetic friction caused by the CDs and the ground: the car has resistance when the car is stopping its movement.
- Kaylee and I had a problem with the front wheel. At first, the hangers were pushed too close together, causing the bottle caps and metal rod to turn with a lot of difficulty. Velvet's issue was solved as we re-glued the hangers further apart.
- With no friction at all, Velvet's wheels would not have rolled. Kaylee and I used a balloon to cover the CD wheels in order to produce traction with the ground! A great advantage!
C.)
- We only had 3 CDs. Because of this lack of materials, Kaylee and I decided to make a tri-pod car. We used CDs because they are perfectly circular, and they were big in size. The bigger the radius of each wheel, the further the car travels with each revolution.
D.)
- The conservation of energy is where energy cannot be created nor destroyed...it is merely transferred into another form. Energy = the capacity for an object to do work.
- The energy could have been transferred into heat, sound, and/or vibrations. When Velvet moved, not all of the work input was equal to the work output.
E.)
- Though we had no extended lever arm, the mousetrap metal lever provided a very short one. The string that was attached to this "lever" was a certain distance from the spring. This created more torque (rotating force). *Torque = Force x Distance
- The lever arm of the metal spring (the actual trapper of the mice) was pulled backward to load. As the metal rod was let go, the string was pulled. This pulling force allowed for the back axle to rotate, causing the wheels to rotate as well. The bigger the lever arm, the more torque.
- The power output of Velvet was the work done/time. The power could be calculated if we can figure out the total work done. I cannot.
F.)
- Rotational Inertia (RI) is the inertia a rotating object has, but is not dependent on how much mass that object has, but where it is distributed. When most of the mass is located furthest from the axis of rotation, there is more RI; when most of the mass is located closest to the axis of rotation, there is less RI. Velvet had a relatively small RI because the mass of the CDs was spread out, but the hole in the middle of the CDs gave Velvet that little "umph."
- The more rotations the CD makes per time interval means that Velvet had a big Rotational Velocity (RV). The bigger the CD, the less rotations it has to make in order to cover a large distance.
- The Tangential Velocity (TVel) of the CD is simply distance/time. But, the inside ring of the CD has a smaller TVel because it covers less distance than that of the edge of the CD.
G.)
- The spring does no work on the car because the force it uses to propel the car is not parallel to the distance in which it travels.
- The potential energy (PE) cannot be calculated because it is not at a specific eight. It is on the ground. The PE must be a constant 0 joules. The kinetic energy (KE) cannot be calculated because the velocity is unknown and changes over time. KE = ? joules.
- The force of the spring cannot be calculated either. This is due to the velocity. We don't know the velocity, or the distance, at which the spring "spring" so the force is unknown.
PICTURE OF VELVET:
The bottle caps supported the CDs on the axle (metal rod).
The mousetrap was securely fastened on the hangers with hot glue.
The string was wrapped around the back axle rod, and tied to the lever arm part of the mousetrap.
The balloons were wrapped around the CDs to created traction on the ground.
The big paper clips were flattened, (Kaylee hammered them!), and glued to the hangers for the body's support.
That was all! Simple but sturdy.
REFLECTION:
- Our original design was a 4-wheeled wooden car, that included 2 large wheels and 2 small wheels. Our axles were going to be flattened paper clips. Our final design was much more efficient, because we used 3 wheels of the same size, and felt hangers for the body (less mass). When Kaylee and I researched more online, we found that these changes were beneficial and ultimately made our car better in all.
- Our major problem was the front wheel. The bottle caps were not completely aligned, so the wheel and the car veered to the right every time we did a trial run. To fix this, I drilled the hole in the hanger lengthwise, so that when I hot-glued the metal axle rod onto it, the CD would then be straight. It was successful!!
- To make Velvet faster, if I did this project again, I would make a lever arm that snapped quickly when the mousetrap was let go, in order to maximize the pushing force. Also, I'd use a thinner string so when wound up, it would not get caught.
A VIDEO OF OUR RACE: BUT NOT THE OFFICIAL, FASTEST ONE:
Again-- 2.84 seconds. I'm so proud.
Thanks Kaylee for being such a great partner!!
CHEERS.
