About how far apart must you hold your hands for them to be separated by 1.6 nano-light-second (the distance light travels in 1.6 ns)? Assume that the speed of light is 2.998*108 m/s.

d = 0.479 m

Explanation:

Given that,

The distance light travels in  = 1.6 ns

The speed of light is

The speed of an object is given by distance traveled divided by time.

Hence, the required distance is 0.479 m.

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.