1 astronomical unit = 149597870700m
Enrico should divide distance in meters with this number.
You need to find the mass of water in the pool.
Find the volume (10 x 4 x 3) = 120 m3
Water has a density of 1000g/m3,so 120 m3 = 120 x 1000 = 120 000 kg
[delta]H = 4.187 x 120 000 x 3.4 (and the units will be kJ)
You then use the heat of combustion knowing that each mole of methane
releases 891 kJ of heat so if you divide 891 into the previous answer,
you will get the number of moles of CH4
Answer:

Explanation:
initially the merry go round is at rest
after 6.73 s the merry go round will accelerates to 20 rpm
so final angular speed is given as



so final tangential speed is given as


now average acceleration of the girl is given as



Relative motion means a motion relative to a reference point. We can also say, relative motion means motion referred or observed from a reference point.
For example, Alex is in a train and Ace is at the station, when the train starts moving, for Ace it is moving at a speed of 10 m/s, but for Alex it is moving at 0 m/s, or we can say that it is at rest for Alex, but in motion for Ace. This is relative motion.
I would have to say B failed because I think I read something about it being only 2law not 3