i need someone to do my Physics lab Report

Experiment 2

Newton’s Second Law

(Room S220)

Goal: To test Newton’s Second Law by predicting and then measuring the motion of an Atwood’s Machine.

General Approach:

We will (1) Use Newton’s Second Law to model the forces acting on an Atwood’s Machine, and to predict the acceleration of the masses; (2) Collect y vs. t data for the motion of the masses; (3) Calculate the actual acceleration of the masses based on our data; (4) Compare the actual acceleration with the predicted acceleration.

The instructor may provide an Excel template which you may use to log data. The template includes the calculations needed for this experiment.

1. Select a small slotted mass to add to one of the (approximately) 200 gram masses that come with the Atwood machine, one large enough so as to produce a uniform acceleration, yet small enough to assure reasonably large times of flight. (Try a mass difference of around 10 grams).

1. Select a travel distance y (say 50 cm). Run the experiment three times. Log the three elapsed times.

1. Repeat step 2 for four more travel distances y.

1. Compute a for each value of y selected and compare. These values of a should be the same to within experimental error.

1. Confirm that a is constant within experimental error, if m1 and m2 are constant.

Data and Calculations

m1 = ________________(smaller mass) m2 = ______________ (larger mass)

Average a = ____________

Sample calculation of a for a given y:

Uncertainty in a, (refer to Lab info handout):

____________.

Standard deviation in a, (refer to Lab info handout)

σa= _____________________

Result: a = _____________ ± _____________.

Lab Report

Your lab report should follow this format:

1. 1. Experiment Design: Sate the goal of the experiment. Describe (both verbally and with pictures) how you collected your data. How was the data used to accomplish the goal? (1 point)

1. 1. Prediction: Draw a free-body diagram for the Atwood’s machine, and use Newton’s Second Law to predict what the acceleration of the masses should be. This is the theoretical value for a. (2 points)

1. 1. Data: Print out/turn in the table of the data you collected. (2 points)

1. 1. Analysis: Use the kinematics equations to show how you can use your measurements of y and t to calculate the acceleration a of the masses. Then state the average result you got for a from your experiment. Also state the standard deviation, σa and the experimental uncertainty,. (2 points)

1. 1. Identify Errors: List several sources of systematic and random errors in your experiment. You should be able to come up with at least two sources of systematic error, and one source of random error. For each source of error that you list, briefly (2-3 sentences) describe why you identified it as a source of error. Note: There is no such thing as “human error”! (1 point)

1. 1. Evaluate Results: Discuss your results (1 paragraph). In particular, state whether your experimental value for a agrees with your prediction (i.e., is the measured value of a consistent with the theoretical value you calculated, taking into account standard deviation/experimental uncertainty. Be specific. Give at least two ways that you could change the experiment to get a more accurate result (hint: how could you change the experiment to minimize the errors you identified in part (d)?) (2 points)

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