Find a formula for the change in surface area of a uniform solid sphere of radius r if its coefficient of linear expansion is α (assumed constant) and its temperature is changed by δt.

i know the answer isδa = 8π r^2αδt [1+(1/2)αδt]

and that the problem involves linear expansion, but im not sure how to arrive at this equation. explain and show steps.

2.22/3.33 points | previous answers tamucolphysmechl1 4.pre.002. ask your teacher my notes question part points submissions used on a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 2.40 m/s. (a) what are the magnitude and direction of the velocity of the red glider after the collision? magnitude 3.33 m/s correct: your answer is correct. direction correct: your answer is correct. (b) is this collision elastic?

Should we celebrate the voyages of zheng he mini q answer key

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano.the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? positive force → balanced force → negative force negative force → balanced force → positive force positive force → unbalanced force → negative force negative force → unbalanced force → positive force