An olympic runner completes the 200-meter sprint in 23 seconds. what is the runner’s average speed? (round your answer to the nearest tenth of a meter per second.)

What is the order of the moon, earth, and sun in a lunar eclipse and a solar eclipse?

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?