An elastic material of length 3m is to be stretched to reduce an extension three times its original length. Calculate the force required to produce the extension

In a solar panel for heat supply, state the function of each of the following parts: (a) metal flat plate; (b) thermal insulator: (c) tubes.

(a) In the design of an optical fibre, what type of material is most suitable for the design of the core?

(b) State one condition necessary to confine signals to the core of an optical fibre.
 

The velocity v, of a wave in a stretched string, depends on the tension T, in the spring and the mass per unit length of the spring. Obtain an expression for v in terms of T and u, using the method of dimensions.

A satellite launched with velocity V\(_E\) just escapes the earth's gravitational attraction. Given that the radius of the earth is R, show that V\(_E\) = \(\sqrt{20R}\) [g = 10ms\(^{-2}\)