4. How long would it take for a water balloon to fall 39 m if we dropped it starting from rest down an elevator shaft from the 13th floor? Ignore air resistance and use a = -9.8 m/s2.
x, = x + vt + (1/2) a t?

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

Explain why you think this diagram shows what happened to the carbon in the biodome.

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