A2 /EXPT/THER/RON/FIONA

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Published on October 10, 2009

Author: ramphy

Source: slideshare.net

To identify the specific lantent heat of water by electric method Ron & Fiona

Steps to Follow Weigh the mass of water, m Put the glass of water into a heat insulator Set up the circuit shown in the diagram Measure the initial temperature of water, T 1 Read the current from the ammetre, I. And we know the votlage of the battery, V. Switch on. Record the time taken to every 10 degrees rise in temperature of water. Record the times t 1 , t 2 , t 3 , etc.

Weigh the mass of water, m

Put the glass of water into a heat insulator

Set up the circuit shown in the diagram

Measure the initial temperature of water, T 1

Read the current from the ammetre, I. And we know the votlage of the battery, V.

Switch on. Record the time taken to every 10 degrees rise in temperature of water. Record the times t 1 , t 2 , t 3 , etc.

c 3 t 3 c 2 t 2 c 1 t 1 c 5 t 5 c 4 t 4 The specific heat capacity of water (Jkg -1 K -1 ) Time taken to rise 10 o C in Temperature of water

Analysis of data Total energy used: E=VIt From E=cm△t we can get cm△t=VIt Here △t=10 Therefore, c = VIt / 10m Then we get c 1 , c 2 , c 3 … from t 1 , t 2 , t 3 … Now take the average.

Total energy used: E=VIt

From E=cm△t

we can get cm△t=VIt

Here △t=10

Therefore, c = VIt / 10m

Then we get c 1 , c 2 , c 3 … from t 1 , t 2 , t 3 …

Now take the average.

Safety precausions Do not raise the temperature of water to too high, i.e. boiling point. Do not touch the wet wires and resistor.

Do not raise the temperature of water to too high, i.e. boiling point.

Do not touch the wet wires and resistor.

Random error: - heat loss when heating - errors when reading the thermometre Improvements: - use an insulator that fit the glass so that there is as little air as possible in the insulator - do more times to take average (exactly what we have done)

Random error:

- heat loss when heating

- errors when reading the thermometre

Improvements:

- use an insulator that fit the glass so that there is as little air as possible in the insulator

- do more times to take average (exactly what we have done)