Explain anation reaction​

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

To find the work done, the force exerted and distance moved are multiplied. a couch is moved twice before you are happy with its placement. the same force was used to move the couch both times. if more work is done the first time it is moved, what do you know about the distance it was moved? a) when more work was done, the couch was moved the same distance. b) when more work was done, the couch was moved less. c) when more work was done, the couch was moved further. d) when more work was done, the couch wasn't moved at all.

Which method would be best to separate a mixture of sand and gravel