The displacement x of a particle at time t moving under a constant force is t = + 3, x in metre, t in second. Find the work done by the interval from t = 0 to t= 6 s.
Calculate the distance below and above the surface of the earth, at which the value of acceleration due to gravity becomes 1/4th that at earth's surface ?
The acceleration due to gravity at depth x below the surface of earth is
Two cells each of same emf e but of internal resistances r1 and r2 are connected in series through an external resistance R. If the potential difference between the ends of the first cell is zero, what will be the value of R in terms of r1 and r2 ?
A ray of light travelling inside a rectangular glass block of refractive index is incident on the glass-air surface at an angle of incidence of 45°. Show that the ray will emerge into the air at an angle of refraction equal to 90°.
At time t = O, a radioactive sample has a mass of 10 g. Calculate the expected mass of radioactive sample after two successive mean lives.