How fast would a rocket ship have to move to contract 1/4 of its proper length (as obserbed by a stationary object(

In the image, the arrow is pointing to a celestial object. which attribute disqualifies the object from being a planet?

Which of these describe conduction transfer of heat between two objects that are touching transfer of heat by the actual movement of war matter the process in which energy is imitated by one of the object transmitted through space and absorbed by another a process in which energy is released by the molecules breaking apart

Agraduated cylinder contains 63.0 ml of water. a piece of gold, which has a density of 19.3 g/ cm3, is added to the water and the volume goes up to 64.5 ml. calculate the mass in grams of the gold that was added to the water. explain how you got your answer.