What is the frame of reference for a plane moving at 500 km/h?

You can define a frame of reference depending on your point of view, but it would normally be the Earth.

so your answer is THE GROUND

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

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