Afriend tells you that a scientific law cannot be changed. state whether or not your friend is correct and then briefly explain your answer.

Answer with Explanation:

The person stating that the scientific law cannot be changed is not correct in his claim.

A scientific law can be defined as a statement that is deemed to explain or predict a natural process and is validated by repeated experiments.

In the light of above statement we may conclude that if the law is validated by experiments it should not be subjected to change but this is not the case as an experiment may be done in the future that invalidates the law.

A classical example of this case is the whole of Newtonian law of gravitation. Classically if we analyse this law it is perfect to describe the motion of solar system , planets ,satellites found in nature hence we should find it absolutely correct and since rockets are designed on the basis of this law we can safely assume that it is correct but it is not the case as the gravity is described radically differently by Einstein by his general theory of relativity thus invalidating the newton's law of gravity.

But we still use the Newton's law of gravity as the error's that are involved in the results of the newton's law are not significant to influence any radical departure from the design philosophy of objects such as rocket's or satellites. It always boils down to the accuracy that we need but theoretically we can say that newton's law of gravity was invalidated by Einstein's general theoty of relativity.  

1/0.14nm = 10^10/1.4 a lot

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