Establish the theorem that any two-dimen sional riemann manifold is conformally flat in the case of a metric of signature 0, i. c. at any point the metric can be reduced to the diagonal form (+1,-1) say. [hint: use null curves as coordinate curves, that is, change to new co ordinates satisfying and show that the line element reduces to the form and finally introduce new coordinates ! (i+ v)

Asystematic approach to problem solving is called a (an)

The pressure proportional to the area a- inversely b- directly c- increase d-decrease

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.