When marking the fixed points on a thermometer its observed that at 0 degrees ,the mercury thread is of length 1 cm and 6 cm at 100degree .What temperature would correspond to the length of 4 cm

1 answer

To find the temperature corresponding to a mercury thread length of 4 cm on the thermometer, we can use linear interpolation based on the lengths at the fixed points:

  • At 0 degrees Celsius, the length is 1 cm.
  • At 100 degrees Celsius, the length is 6 cm.

We can set up a linear relationship between the temperature (T) and the length (L) of the mercury thread.

  1. Calculate the change in length per degree:

    • Length change from 0°C to 100°C: \(6 \text{ cm} - 1 \text{ cm} = 5 \text{ cm}\)
    • Temperature change: \(100 \text{°C} - 0 \text{°C} = 100 \text{°C}\)

    Length per degree: \[ \text{Length per degree} = \frac{5 \text{ cm}}{100 \text{°C}} = 0.05 \text{ cm/°C} \]

  2. Establish the equation for length: \[ L = 1 + 0.05T \]

  3. Set \(L = 4\) cm and solve for \(T\): \[ 4 = 1 + 0.05T \] \[ 4 - 1 = 0.05T \] \[ 3 = 0.05T \] \[ T = \frac{3}{0.05} = 60 \text{°C} \]

So, the temperature corresponding to a mercury thread length of 4 cm is 60 degrees Celsius.