Calculate the internal energy (in j) of 86 mg of helium at a temperature of 0â°c.

The internal energy is 73.20 J.

Explanation:

Given that,

Weight of helium = 86 mg

Temperature = 0°C

We need to calculate the internal energy

Using formula of internal energy

Where, = specific heat at constant volume

He is mono atomic.

So, The value of

now, 1 mole of Helium = 4 g helium

n =number of mole of the 86 mg of helium

T = 0°C=273 K

Put the value into the formula

Hence, The internal energy is 73.20 J.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000