Star A has twice the radius and twice the absolute temperature of star B. What is the ratio of the power output of star A to that of star B

What best describes a sonar wave? transverse and electromagnetic transverse and mechanical longitudinal and electromagnetic longitudinal and mechanical

Jackson is designing a new heater, and he wants to experiment with different thermally conductive materials. which of these materials would be useful in conducting heat?

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •