In the Tour De France, bicycles are designed to be extremely light, and nearly all competitors' bicycles today weigh just 6.8 kg or 15 pounds. Why would it be a disadvantage for cyclists in this race to ride heavier bicycles? Use Newton's Laws to explain your answer .

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

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?

Suppose a wire with a current is pushed upward by a magnetic field. how would the wire move if the direction of the current reversed? explain your answer.