A worker wishes to pile a cone of sand into a circular area in his yard. The radius of the circle is rand no sand is to spill onto the sorrounding area.if u(mu) is the coffecient of static friction between each layer of sand along the slope and the sand,the greatest volume of sand that can be stored in this manner is

(a)u pi r^3 (b)1/3u pi r^3 (c)2u pi r^2 (d)2u pi r

Three identical balls are placed on a frictionless horizontal surface touching each other. They stick to each other because of adhesive. Another ball of same radius and mass m is placed over the void created by the three balls. Find the forces applied by the balls kept on the floor to each other if the system remains in equilibrium.

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

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