Data Table

Mass of cart / kg
Trial / Final Velocity
vf
/ Initial Velocity
vi
/ Change of Velocity Dv / Average Force
F
/ Duration of Impulse
Dt
/ Calculated
Impulse / Integral
Impulse
Long string / (m/s) / (m/s) / (m/s) / (N) / (s) / (N×s) / (Ns)
1
2
Short string
1
2
Trial / Impulse - Integral`
/ Change in momentum
/ % difference between Impulse and Change in momentum
Long string / (N×s) / (kg×m /s) or (N×s) / (N×s)
1
2
Short string
1
2

Caculations:

Impulse - Change in Momentum Questions

1. Look at your calculated impulses column and integral impulse column. How do they compare with each other? explain

2. If the impulse-momentum theorem is correct, the change in momentum will equal the impulse for each trial. Experimental errors will keep the two from being exactly the same. One way to compare the two is to find their percentage difference. Divide the difference between the two values by the average of the two, then multiply by 100%.

How close are your values, percentage-wise? (words)

Does your data support the impulse-momentum theorem? Explain!

3. Look at and compare the shape of you long string data versus you short string data. Is the peak value of the force significantly different from the average force, in each case?

Is there a way you could deliver the same impulse with a much smaller force? Explain

4. When you use different elastic materials, what changes occurred in the shapes of the graphs?

Is there a correlation between long and short string (type of material) and the shape?

5. When you used a stiffer or tighter (short string) elastic material, what effect did this have on the duration of the impulse?

What affect did this have on the maximum size of the force?

Can you develop a general rule from these observations?

Be sure to check the rubric for all required parts of the lab 20 - 2