/sci/ - Science & Math

>>2587100

mfw

well, kinda like that

20 g of dry ice (solid CO2) is placed in a 2.0*10^4 cm^3 container, then all the air is quickly pumped out and the container sealed. The container is warmed to 0 deg C, a temperature at which CO2 is a gas.

a) What is the gas pressure? Give your answer in atm. The gas then undergoes an isothermal compression until the pressure is 3.4 atm, immediately followed by an isobaric compression until the volume is 2000 cm^3.

b) What is the final temperature of the gas?
I have no fucking clue where to begin. Physics is not my subject...

I am in desperate need of help on this physics problem. I've been going around in circles with it for ages.

An "energy bar" contains 26 g of carbohydrates. If the energy bar was his only fuel, how far could a 68 kg person walk at 5 km/hr ?

What I have so far:

26g of carbs = 104 calories which is 435 joules.
5 km/hr = 1.389 m/s
Kinetic energy = 1/2(68*1.389*1.389)=65.59 joules
Weight force = 68*9.8=666.4 N

I thought I understood it, but my answers have all been wrong. I'm lost and confused. Please help me!