Is it possible for one ray to be shorter in length than another?

Yes, even light rays can vary in wavelength and frequency, if the length of the ray is sorter, it becomes more energetic and has a higher frequency. If you're talking about a ray tracing diagram for lenses or mirrors, the length of the ray doesn't really matter unless you're finding the path length but there are some procedures for that too. Let me know if I missed what you were asking.

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.