I need an answer ASAP

Time taken for star to reach Earth = 7.5 years

Given

7.5 light years(distance Earth-star)

Required

Time taken

Solution

Speed of light=v = 3 x 10⁸ m/s

1 light years = 9.461 × 10¹⁵ m= distance(d)

So time taken for 1 light years :

time(t) = distance(d) : speed(v)

t = 9.461 × 10¹⁵ m : 3 x 10⁸ m/s

t = 3.154 x 10⁷ s = 1 years

So for 7.5 light years, time taken = 7.5 years

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.