First, measure the diameter of the metal wire used with a vernier calliper
Do this several times along the wire and calculate the mean diameter (d)
Use equation (½ × d)2 × 𝜋 to calculate the cross-sectional area of the wire
Setting apparatus:
On a bench, clamp one end of the wire between 2 wooden blocks between a G- clamp
On the other side ensure the wire is taut over a pulley and connect to a mass hanger
Place metre rule on the bench below the wire with a tape to act as a marker to measure extension
Measure the initial length of the wire with the rule
Recording Measurements:
Mass (kg) Force (N) Extension (m)
0.1 0.981 0.02
1. On the mass hanger place a mass of 100g
2. Calculate the Force on the wire using equation Mass × Gravitational Field strength (9.81)
Measure the extension of the wire by measure the additional length past the marker
Record values in table
Continue adding 100g masses and recording extension until a total of 1kg has been added
Plot a graph of Force (y-axis) against extension (x-axis) and plot points form table
Draw line of best fit and calculate the gradient