# 568 - Physics Questions Answers

A perfectly elastic particle is projected with a velocity v on a vertical plane through the line of greatest slope of an inclined plane of elevation α.If after striking the plane, the particle rebounds vertically show that it will return to the point of projection at the end of time equal to?

ANS GIVEN -   6V/{g(1+8sin^2(α))^(1/2)}

A small ball of mass 1kg and charge 2 C 3 is placed at the centre of a uniformly charged sphere of radius 1m and charge 1mC 3 . A narrow smooth groove is made in the sphere from centre to surface as shown in figure. The sphere is made to rotate about its vertical diameter at a constant rate of 1 2 revolutions per second. Find the speed w.r.t. ground with which the ball slides out from the groove. Neglect any magnetic force acting on ball

A force acts for 20 seconds on a body of mass 10 kg after which force ceases and the body describes 50m in the next 10 seconds . find the magnitude of the force?

A body first acceleration with alpha m/s^2 and from rest and then retards with beta m/s^2 to rest. The total distance covered is D. So find the total time taken . With only alpha,beta and d terms.

Please explain krotov questions 3.26 of electricity