Popular questions and responses by Liang
  1. chemistry

    A very flexible helium-filled balloon is released from the ground into the air at 20 degree C. The initial volume of the balloon is 5.00 L, and the pressure is 760 mmHg. The balloon ascends to an altitude of 20km, where the pressure is 76.0 mmHg and the

    asked on October 20, 2012
  2. chemistry

    calculate the moles of indicated product produced when 26.0g of each reactant is used. A. 4Al+3O2---->2AlO3 (Al2O3 B. 3NO2+H2O--->2HNO3+NO (HNO3)

    asked on October 19, 2012
  3. chemistry

    How many grams of C3H18O2 contain 7.9 e25 atoms of Carbon?

    asked on October 19, 2012
  4. physics

    A painter in a crate which hangs alongside a building, weighs 1000N.When the painter pull on the rope, the force he exerts on the floor of the crate is 450N. If the crate wieghs 250N, find the acceleration.

    asked on June 13, 2011
  1. physics

    I don't understand how to find the resultant force, who can help me?

    posted on June 14, 2011
  2. physics

    but the answer given is 2?

    posted on June 13, 2011