Newton's 2nd Law Lab

Calculations:

Wt = m * g
= 0.02 kg * 9.8 m/s/s
= 0.196 N

Fnet = m * a
0.196 N = 0.5371 kg * a
a = 0.365 m/s/s

% Error = | (Known - Experimental) / Known | * 100
% Error = | (0.365m/s/s - 0.332m/s/s) / 0.365m/s/s | * 100
% Error = | 0.033 / 0.365 | * 100
% Error = 9.0%

DATA TABLE	1st Trial	2nd Trial
Mass of Cart (kg)	.5171	.5171
Mass of Hanging mass (kg)	.02	.05
Total Mass of System (kg)	.5371	.5671
Weight of Hanging Mass (N)	.196	.49
Acceleration (m/s/s) Slope "a2"	.332	.877
Acceleration (m/s/s) calculated	.365	.864
% Difference	9.0	1.5

Questions:

1. What is the % difference between the measured and theoretical accelerations?

1st trial
abs(0.365 - 0.332) / 0.332 X 100 = 9.0%

2nd Trial
abs(0.864 - 0.877) / 0.877 X 100 = 1.5%

2. List two possible reasons for any differences between the measured and calculated values.

• Friction between the cart and the track may have slowed the cart's acceleration.
• The string connecting the cart and hanging mass may have had a tension force that affected the results.

Tension does not affect results......tension pulling hanging mass up would cancel out the same tension value pulling the cart across.

14/15


3. If you add more mass to the hanging end, what effect would that have on the acceleration?

The acceleration would be greater because the weight of the hanging mass would therefore increase.

4. If you increased the mass of the cart itself, keeping everything else constant, what effect would that have on the acceleration?

The acceleration would decrease because it requires more force to

5. If you added a LOT more weight on the hanging mass end, what would the acceleration value be (approximately)?

9.8 m/s/s in the downward direction, or g