PRACTICALS

Question 1

Describe an experiment to investigate spring extension

Answer 1

1. Set up the apparatus by attaching a spring to a clamp stand, and using another clamp stand to hold up a meter ruler next to the spring . Add a marker to the spring to make readings more accurate.
2. Measure the original length of the unstretched spring.
3. Add a known weight to the spring and allow it to come to rest. Record the weight and the new length of the spring.
4. Calculate the extension by doing the new length of the spring subtract the original length of the spring.
5. Continue adding weights and calculating extension until 8 weights have been added.
6. Plot a force-extension graph of results

Question 2

Describe a risk assessment for the spring extension experiment

Answer 2

Hazard: spring under tension so may snap

Consequence: damage to eyes, cuts to skin

Protective measures: wear eye protection

Question 3

Describe an experiment to find the Young modulus of a wire material?

Answer 3

1. Draw diagram of the apparatus (includes the test wire, a marker on the wire, a pulley, a ruler with mm markings, clamps, and masses)
2. Use a micrometer to measure the diameter of the wire in several places, then take an average of the measurements
3. Record the starting position of the marker
4. Measure the distance between the fixed end of the wire and the marker to find the unstretched length
5. Add masses to the wire until you reach 8, weighing the masses and using m x g to find the force for each mass
6. Record the total force applied and the marker reading each time a new mass is added
7. Calculate and record the extension for each total force applied by finding the difference between the new marker readings and the original marker readings
8. Repeat the entire experiment at least two more times and calculate average extensions for each force

Question 4

How can you determine the Young modulus of a wire material from the Young modulus experiment?

Answer 4

-Calculate the area of the wire by doing πr^2
-Plot a graph of extension (y-axis) against force (x-axis)
-The Young modulus is
(1/gradient) x (L/A)