Done by Yovaphine Wijaya – 11 Science 1

Aim

To investigate Hooke’s law for simple strings or rubber.

Hypothesis

The change in length of spring is directly proportional to the applied so that it will cause greater change in length of the spring for greater force applied. It is supported by the formula of force, F = kx, where F is the applied force, k is the spring constant of the spring, and x is the change in length or extension of the spring. Since the spring used is the same, the spring constant will always be the same for any value of force applied and extension of the spring.

Theory

The relationship between a load force and a light spring (F = kx) was the first determined by Robert Hooke in the 17th century. Hooke’s law states that when an elastic material is subjected to a force, its extension (Δx) is proportional to the applied force. The value of k is constant for a particular spring. When an elastic material is subjected to a force, its extension (Δx) is proportional to the applied force, the value of k is constant for a particular spring.

Variables

Independent Variable

The applied force calculated by using the formula F = mg, where F is the applied force in Newton (N), m is the mass of the load measured by using an electronic balance in gram (g), and g is the gravitational acceleration in m/s2, which is a value constant (9.8m/s2).

The mass of load measured by an electronic balance (30.00 ± 0.01g, 50.00 ± 0.01g, 100.00 ± 0.01g, 150.00 ± 0.01g, and 200 ± 0.01g).

Dependent Variable

1. The final length of the spring measured by using a plastic ruler in meter (m) 2. The extension of the spring calculated by using the formula of x = x1 – x0, where x is the extension of the spring, x1 is the final length of the spring and x0 is the initial length of the spring measured by using a plastic ruler in meter (m). 3. The constant spring of the spring calculated by using the formula of F = kx in N/m

Control Variables

* The type of the spring used is same with an initial length of 0.140 ± 0.0005m measured by using a plastic ruler. * The spring and load’s temperatures followed the temperature of the room, which is 25.00 ± 0.05oC measured by using a room thermometer.

Apparatus

Materials| Quantity| Limit of Reading| Serial Number|

Clamp| 1| -| -|

Electronic balance| 1| Δm = 0.01g| -|

Load| 5 (30.00 ± 0.01g, 50.00 ± 0.01g, 100.00 ± 0.01g, 150.00 ± 0.01g, and 200 ± 0.01g)| -| -| Plastic ruler| 1| Δx = 0.0005m| -|

Spring| 1| -| -|

Table| 1| -| -|

Method

1. Weigh the 5 loads using an electronic balance and record them. 2. Measure the temperature of the room by using a room temperature and record it. 3. Measure the initial length of the spring using a plastic ruler and record it. 4. Attach the spring to the clamp and plastic ruler next to the spring. 5. Hang a load at the hanging spring. Measure the final length of the spring by using the plastic ruler and record it. 6. Repeat step 5 for the other independent variables and trials (10 trials for each independent variable).

Diagram of set up apparatus

Data Collection

Table 1. Table of final length of spring for 30.00 ± 0.01g of load Trial| Final Length of String (m), Δl = 0.0005m|

1| 0.200|

2| 0.200|

3| 0.198|

4| 0.201|

5| 0.200|

6| 0.198|

7| 0.200|

8| 0.202|

9| 0.200|

10| 0.200|

Table 2. Table of final length of spring for 50.00 ± 0.01g of load Trial| Final Length of String (m), Δl = 0.0005m|

1| 0.240|

2| 0.241|

3| 0.240|

4| 0.241|

5| 0.240|

6| 0.241|

7| 0.240|

8| 0.241|

9| 0.240|

10| 0.240|

Table 3. Table of final length of spring for 100.00 ± 0.01g of load Trial| Final Length of String (m), Δl = 0.0005m|

1| 0.340|

2| 0.338|

3| 0.338|

4| 0.339|

5| 0.340|

6| 0.340|

7| 0.341|

8| 0.341|

9| 0.340|

10| 0.340|...