Earth's atmosphere actually decreases you weight, due to the minute effects of buoyancy with the air. Even though there are tons and tons of atmosphere on us, the preasure is balanced by the internal pressure within our bodies, just like with fish in deep water that have tons and tons of water pressing in on them.
The average different that the air has on us is about 40-55 grams (or .09 - .12 lbs).
The weight.
atmosphere
Payload weight
Payload weight
No, your weight is just the acceleration due to the Earth's gravity,
The atmosphere becomes less dense with altitude. Atmosphere, thin though it is, has weight, and it is the weight of the air above which compresses the air below it, to greater density.
There is air pressure in that bag too
Moon gravity is less because the atmosphere and mass and the earths gravity is greater than the moon if you weight yourself in the earth and then you weighted yourself in the moon you would weight less in the moon you could actually float in the moon because of its atmosphere and mass
The heat would make no difference, but the atmosphere would increase the weight.
It decreases
The pressure inside the bag is the same as the pressure outside.
It will decrease not by much though it is not noticeable compared to the earths radius