A58.1 kg wood board is resting on very smooth ice in the middle of a frozen lake. a 48.3 kg boy stands at one end of the board. he walks from one end of the board to the other end with a velocity of 1.69 m/s relative to the ice in the positive direction. what is the velocity of the board relative to the ice? -1.69m/s

V = 1.41 m /s

Explanation:

Movement in both wood board and boy is created by internal forces . No horizontal external force acts on them . So conservation of momentum will apply on both of them for movement in horizontal direction.

Mass of wood board x velocity = mass of boy x velocity

58.1 x V = 48.3 x 1.69

V = 1.41 m /s

found in the nucleus

has mass of one amu

this means that the temperature of both substances will be equal