two objects of inertias M1 and M2 start from rest and then interact with each other (assume neither is interacting with any other object ). (a) what is the ratio of their X components of velocity at any instant? (b) what is the ratio of their kinetic energies at any instant?​

You can decrease the resistance of a length of wire by

Amerry-go-round of radius r, shown in the figure, is rotating at constant angular speed. the friction in its bearings is so small that it can be ignored. a sandbag of mass m is dropped onto the merry-go-round, at a position designated by r. the sandbag does not slip or roll upon contact with the merry-go-round. how would you rank the following different combinations of m and r on the basis of the angular speed of the merry-go-round after the sandbag "sticks" to the merry-go-round from largest to smallest. a) m = 10kg, r = 0.25r b) m = 20kg, r = 0.25r c) m = 10kg, r = 0.50r d) m = 10kg, r = 1.0r e) m = 15kg, r = 0.75r f) m = 40kg, r = 0.25r

Definition: this is the weighted average of all of the isotopes of an element.