Answer:
mass conservation is valid for all closed system where the mass will remain in the system always
Explanation:
Conservation of mass is applicable everywhere in classical physics
Here we can also apply mass conservation as we know that the initially the beaker and its water content is having total mass of 109.44 g

now when we heated it to higher temperature then its total mass will be lesser than the initial mass this is because some of the water may evaporate from the system.
Here if we repeat the same experiment with closed boundary then we can see that total mass will be conserved
So here mass conservation is valid for all closed system where the mass will remain in the system always
The first thing that needs to be done is to find everything in the same units. 12 hours becomes 43200 seconds. Then find the distance traveled by light in that amount of time. Using the formula v=d/s, manipulate it so it looks like d=v*s. Then plug in the values: d=(3x10^8)*43200, d=1.3x10^13m. But you need to find this in kilometers. To do this, simply divide your answer by one thousand. Thus, a laser beam would travel 1.3x10^10 kilometers in 12 hours.
Answer:
248 minutes
Explanation:
6200/25=248
This means there is 248 25s in 6200
which means it will take 248 minutes to travel through the river
Also here's a neat trick:
The units for speed is meters/minute
The units for distance is meters
Dividing distance by speed will cancel out the meters and leave only the speed.
If the same atoms appear on both sides, then it's balanced.
In this reaction, there are 4 Oxygens, 2 Carbons, and 2 Nitrogens on each side. So numerically, <em>it's balanced</em>. But I don't know enough chemistry to say whether the reaction is possible.