A man is walking to the right with a speed of 2.0 m/s. He then speeds up to 5.0 m/s. During this he travels 100 m. a. How long did the change in speed take?

b. What was the mans average acceleration?

The 20@kg wheel has a radius of gyration about its center g of kg = 300 mm. when it is subjected to a couple moment of m = 50 n # m, it rolls without slipping. determine the angular velocity of the wheel after its mass center g has traveled through a distance of sg = 20 m, starting from rest.

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?