Phys4AS17 jsong

Purpose Find the relationship between air resistance and velocity of falling coffee filters. Process First, drop those coffee filters at the technology building’s indoor balcony. Take five clips for different amounts of filters. So that we finish the very first step of this lab. Then use logger pro to analyze the videos, which can give us data needed in the lab. We will get five velocity verse time plots. From it we can derive terminal speeds. Amount of coffee filters Terminal speed 1 1.2068 2 1.7117 3 2.1317 4 2.4631 5 2.7491 Data Analyze Then we should try to match the plot to the formula F= K * V^n. The matching result shows that K=0.5989 and n=1.958. With these two values, we can derive a calculating answer for this problem. First we get eight columns named as t, delta v, v, a, delta x, and x. We set the time to 0.01 secon...

Propagated Uncertainty in Measurements Purpose Learn how to calculate propagated uncertainty in density measurements with different metal material cylinders. Process First, we need to measure the density of two cylinders made of different materials . To measure the density we should measure its mass m, diameter d and height h. Mass(g) Diameter(cm) Height(cm) 69.4 1.55 5.01 27.6 1.59 4.98 So the density of the first material is about 7.31 g/cm^3, which may be zine. The density of the second material is about 2.80 g/cm^3, which may be aluminum. Then we should calculate the propagated uncertainty of the density. For a cylinder, its density can be calculate with the equation p=(4/∏)* [m/(d2*h)]. The differential form of this equation is dp= (∂p/∂m)*dm + (∂p/∂d)*dd + (∂p/∂h)dh, which equals to The calculation is attached below. Conclusion In this lab, we learnt ho...

Purpose Solve non-constant acceleration problem by both numerical approach and analytical approach . Here is the question. A 5000-kg elephant on frictionless roller skates is going 25 m/s when it gets to the bottom of a hill and arrives on level ground. At that point a rocket mounted on the elephant’s back generates a constant 8000 N thrust opposite the elephant’s direction of motion. The mass of the rocket changes with time (due to burning the fuel at a rate of 20 kg/s) so that the m(t) = 1500 – 20t. Find how far the elephant goes before coming to rest. Numerical Approach 1.      Put appropriate values in for Vo and Xo. 2.      Set Δt to be 1 second. Put in the other appropriate values in cell B1 through B4. (Recall that the force is negative here, since it points in the negative x-direction.) 3.      Input a formula into cell A9 that will calculate the appropriate time, and that you can...

Purpose Determine the gravity coefficient by determine the velocity of a falling object with spark generator and spark–sensitive tape. Compare the result  with the actual value to calculate the error from systematic nature. Procedure The spark generator is connected to a cylinder which would fall with a distant of 1.5 m and was linked with the spark-sensitive tape. When the cylinder released, the spark generator left sparks on the tape with a frequency of 60 per second. After measuring the distant between sparks and analyzing those data, we can finally get the local gravity coefficient. Method of Fitting From the sparks we can derive the time of each spark. To ensure the velocity’s accuracy, we should choose a mid-interval time and the corresponding mid-interval velocity. When we plot velocities in excel and plot the fitted curve, the slope of the fitted curve is the gravity coefficient. Conclusion and Analysis The gravity coefficient determined by...

Physics 4A, Lab 1: Author: Jiarong Song (Nina), Joel Date of Lab: Feb 27 Purpose Statement:    To determine the inertial mass of an unknown object by using the relationship between mass and period on an inertial balance, and using this model to determing the unknown masses of some other objects. Procedure: Use a C-clamp to secure the inertial balance to the tabletop. Put a thin piece of masking tape on the end of the inertial balance. Set up a photogate so the when the balance is oscillating the tape completely passes through the photogate. Hit collect and pull back the release the inertial balance the computer starts measuring a reasonable period. Record the period with no mass in the tray first. Adding 100g each time and record the data in table. Measured data: Mass in balance (g) Period (sec.) Mass in balance (g) Period (sec.) 0 0.283 500 0.547 100 0.346 ...