Mouse Trap Car Project

I. Intro
  By using a mousetrap as a single power generator, students had to build a car that can go at least five meters.
II. Hypothesis
  As the force is proportional to the mass and acceleration, the heavier a car is, the slower and lesser the car will go.
III. Project
  Daniel and Armoni met few times at evenings in each other's houses for average two hours. At sunday, we built the basic design. At monday, we checked that we had some technical difficulties to carry out the design. Thus, we decided to use last year's leftovers instead. It turned out that the last year's one was too heavy. The body's conjuncture point with the wheels also had so much friction as well. At last day, we finally figured out how to use the last year's one.
IV. Success and Failures
   The car was relatively light, so it went all it could go in a few quick seconds. The technique we used to move the car caused so much friction in the axis of the wheel that we assume we lost much power. After tying the string in the axis, we put it in the base of a car that has a hole for the string to come out. When we actually used it, the string had to have the force enough to turn the axis as well as to move the axis enough for the string to be in line with the hole.
V. Discoveries
   .We found out that the wheels had to have certain amount of friction to flowly go on a surface. We discovered that the stick that we used is better off when it's long because of basic principles of torc power. However, the length had to be enough for the stick not to break off. The wheel, in the same way as the stick, is better off when it is large. However, it can't be too heavy.
VI. Laws
    F=ma
    Torque=Fr
    Friction= coefficent of friction * Normal force
VII. Conclusion
    The lighter, the faster. However, it doesn't always mean the longer because the car has cerain efficiency in using power.

Experiment : Trajectory LAB

Daniel Jung
Eddie Park, Peter Han
Physics/ 2
Mr. Elwer
Procedure
    1. Prepare materials : balls , cones for measurement, a tape measure, angle measurers.
    2. Go to an even field.
    3. Stand in an appropriate place to throw and set an approximate point for the ball to fall.
    4. Find the midpoint between the throwing point and falling point.
    5. Another person have to stand on the midpoint. Step back perpendicularly so that the person can measure the angle of the ball in the air.
    6. Throw the ball.
    7. The second person will measure the angle of the ball at the highest point by using the angle measurer.
    8. The other person will set the cone at the point at which the ball's dropped at.
   
    9.  Measure the distance between the starting point and the dropped point.
   10. Calculate the initial velocity of the ball.



















< The ball's thrown by x degree from the horizontal line>

Data&Analysis

Trials	1st	2nd
Distance	15.9m	15.0m
	15.45m
Angle	52⁰	60⁰
Average Height	12m

    1. The highest height can be measured by trigonometric method. We can get the averaged length by calculating (2.0+7.0tan52+2.0+7.0tan60)/2 = 12.
    2. Using the background knowledge that the ball's vertical velocity is zero at its highest point, we can come up with this equation. -12 indicates the height.

h = h_i + v_it + at²/2= (-12) = 2+ 0 + (-9.81)t²/2

t= 1.689 = 1.7s (the time for the ball to reach its highest point)

Then, we can figure out the initial, vertical velocity (v_y).

0 = v_y + at = v_y + (-9.81)(1.689)
Thus,
v_y = 16.5735 = 17 m/s

As the horizontal velocity is constant,

v_x = 15.45/1.689 = 9.14742 = 9.1 m/s

Using pitagorian theorem,

vi = (9.1² + 17² )^1/2= 19 m/s

Degree x= arctan((12-2)/7.725) = 54 degrees