Chapter 1 (Measurement) Numerical Problem 1.1

NUMERICAL PROBLEM

PROBLEM 1.1 :
A light year is the distance light travels in one year. How many meters are there in one light year: (speed of light=3.0x10⁸ms⁻¹)

SOLUTION:

Given data:
                       time= t =1 year = 365 days.
Therefore,
                                  t = 365 x 24 x 60 x 60 s
                                    = 31536000 s
                                    = 3.154 x 10⁷s
Speed of light  =     v = 3.0 x 10⁸ ms⁻¹
To determine:
                   Distance= S = ?
Calculation:
we know that:
                    S  = vt
Here            V = c
                     S = ct
Now substituting the value we have;
                      S = 3.0 x 10⁸ ms⁻¹ x 3.154 x 10⁷s
Or
                      S = 9.5 x 10¹⁵  m      Ans.