Summary of story the face on the wall by E.V.LUCAS....

A man is sitting in a room at 2m from a wall W_1 , wants to see the full height of the wall W_2 behind him 4m high and 6m away from the facing wall W_1 . What is the minimum vertical length of mirror on the facing wall required for the purpose?

A particle of mass m strikes a wall with speed v at an angle 30^(@) with the wall elastically as shown in the figure. The magnitude of impulse imparted to the ball by the wall is

A ball of mass m collides with a wall with speed v and rebounds on the same line with the same speed. If the mass of the wall is taken as infinite, then the work done by the ball on the wall is

A ball rolls without sliding over a rough horizontal floor with velocity v_(0)=7m//s towards a smooth vertical wall. If coefficient of restitution between the wall and the ball is e=0.7 . Calculate velocity v of the ball long after the collision.

S,O & W represent source of sound (of frequency f), observer & wall respectively. V_0, V_S, V_D,V are velocity of observer, source, wall & sound (in still air) respectively. V_W is the velocity of wind. They are moving as shown. Find The wavelength of the waves incident on the wall.

A Sphere moving with velocity v strikes a wall moving towards the sphere with a velocity u. If the mass of the wall is infinitely large the work done by the wall during collision will be: