If the decomposition of hydrogen peroxide is a first order reaction and it takes 20.0 minutes for the initial concentration to fall from 1.6m to 0.80m, how much time has passed when only 0.050m remain
a) 80 min
b) 120 min
c) 100 min
d) 40 min

Asmall object with mass 0.200 kg swings back and forth on the lower end of a light rope that is 3.00 m long. the upper end of the rope is attached to the ceiling. as the object swings through its lowest position, where the rope is vertical, the speed of the object is 5.80 m/s. at this point in the motion, what is the tension in the rope? (use g = 9.80 m/s2.)

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

Atank has a shape of a cone with a radius at the top of 2 m and a height of 5 m. the tank also has a 1 m spout at the top of the tank. the tank is filled with water up to a height of 2 m. find the work needed to pump all the water out the top of the spout. (use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3.)