The graph displays the temperature over time for an unknown substance. Which of the following correctly identifies segment XY and why?

A.
Melting, because the substance has a freezing/melting point of 290°C.

B.
Melting, because energy is being added, but the temperature is not changing

C.
Vaporization, because the substance cannot be heated beyond a temperature of 290°C.

D.
Vaporization, because energy is being added, but the temperature is not changing.

Suppose an objects initial velocity is 10m/s and it’s final velocity is 4 m/s. mass is constant. what can best be concluded about the object based in the work-energy theorem

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

Which of the following is the largest disadvantage of about half of the electricity in the united states comes from burning