Hook's Law

Equipment: -

o Spring

o Ring Stand

o Ring-Stand Clamps

o C-Clamps

o Spring Scale

o Ruler or Meter Stick

o Set of Known Masses

Procedures: -

) Assemble the apparatus, and be sure to clamp the ring stand to the lab table, or weight it with several books.

2) Construct a data table. You will need to record the mass that you hang from the spring and the position of the end of the spring before and after the mass is added. From this, you will calculate the force applied to the spring and the resulting stretch of the spring. You should allow for at least 8-10 trials.

3) For each trial, record the mass, the starting position of the spring (before hanging the mass) and the ending position of the spring (while it is being stretched).

Results: -

) Calculate the force applied to the spring in each trial (W = mg). Use g = 9.8m/s².

2) Calculate the stretch of the spring band in each trial (the difference in the starting and ending positions).

3) Draw graphs of force versus stretch for the spring.

Data Collection: -

Mass / g

(± 0.01g)

Length / cm

(± 0.05)

0

0.1

20.55

0.3

41.89

.2

62.87

2.9

83.62

4.6

04.18

6.3

24.92

8.0

Data Processing: -

Note: Lo = Initial length of the spring

Mass

Force (mg)

Extension (L - Lo)

0

0 · 9.8 = 0

0.1 - 0.1 = 0

20.55

20.55 · 9.8 = 201.39

0.3 - 0.1 = 0.2

41.89

41.89 · 9.8 = 410.522

.2 - 0.1 = 1.1

62.87

62.87 · 9.8 = 616.126

2.9 - 0.1 = 2.8

83.62

83.62 · 9.8 = 819.476

4.6 - 0.1 = 4.5

04.18

04.18 · 9.8 = 1020.964

6.3 - 0.1 = 6.2

24.92

24.92 · 9.8 = 1224.216

8.0 - 0.1 = 7.9

Data Presentation: -

The constant "k" is called the spring constant, and it depends on the type and material of the spring.

k = F / x

k can be determined from the graph by calculating the gradient of the graph (Y2 - Y1 / X2 - X1)

k = gradient

High k value means high stiffness

k = (Y2 - Y1 / X2 - X1)

k = (1224.216 - 0 / 7.9 - 0)

k = (1224.216 / 7.9)

k = 154.9640506

Conclusion: -

The force applied to the spring by the mass can be found by the equation F = mg, which is the mass of the object on the spring times the gravitational constant, which in this experiment was taken as 9.8 m/s². The extension of the spring can be found by measuring the length of the spring before, and after the weight is placed on the spring, then subtracting the length of the spring with the weight on it, by the length of the spring before the weight was put onto it.

There were many errors in this experiment, which were mostly human errors. One of the errors could be from reading the length of the spring, using a ruler. The spring was bouncing, so this could have leaded us to read the ruler incorrectly. A way to prevent this error would be to, after placing the weight onto the spring, to leave it alone in an environment which would not shake it, until it stopped bouncing, and we could accurately read the ruler.