Two men to masses `80kg` and `60kg` are standing on a wood plank of mass `100kg`, that has been placed over a smooth surface. If both the men start moving towards each other with speeds `1m//s` and `2 m//s` respectively then find the velocity of the plank by which it starts moving.

Two particles of masses 1kg and 2kg respectively are initially 10m aprt. At time t=0 , they start moving towards each other with uniform speeds 2m//s and 1m//s respectively. Find the displacement of their centre of mass at t=1s .

Two particles of masses 1kg and 2kg respectively are initially 10m aprt. At time t=0 , they start moving towards each other with uniform speeds 2m//s and 1m//s respectively. Find the displacement of their centre of mass at t=1s .

A man of mass m is standing on a plank of equal mass m resting on a smooth horizontal surface. The man starts moving on the plank with speed u relative to the plank. The speed of the man relative to the ground is

A man of mass m is standing on a plank of equal mass m resting on a smooth horizontal surface. The man starts moving on the plank with speed u relative to the plank. The speed of the man relative to the ground is

Two particles A and B of equal size but of masses m kg and 2m kg are moving directly towards each other with speeds 21 m//s and 4 m//s respectively. After collision, A moves with a speed of 1 m//s in the original direction. Then:

A horizontal turn table of mass 90kg is free to rotate about a vertical axis passing through its centre. Two men – 1 and 2 of mass 50kg and 60kg respectively are standing at diametrically opposite point on the table. The two men start moving towards each other with same speed (relative to the table) along the circumference. Find the angle rotated by table by the time the two men meet. Treat the men as point masses.

A horizontal turn table of mass 90kg is free to rotate about a vertical axis passing through its centre. Two men – 1 and 2 of mass 50kg and 60kg respectively are standing at diametrically opposite point on the table. The two men start moving towards each other with same speed (relative to the table) along the circumference. Find the angle rotated by table by the time the two men meet. Treat the men as point masses.

A man of mass 50 kg us standing on a 100 kg plank kept on a fricitonless horizontal floor. Initially both are at rest. If the man starts walking on the plank with speed 6m//s towards right relative to the plank, then amount of muscle energy spent by the man is