A ray of light strikes a plane mirror at an angle of incidence 35°. If the mirror is rotated through 10°.
i. what is the angle of reflection before rotating the mirror?
ii. through what angle is the reflected ray rotated?
iii. what is the angle between the incidence ray and the new reflected ray?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f

If element x has 99 protons how many electrons does it have