During a physical science lab investigating chemical reactions, several students placed a 30g antacid tablet in a 30g zip-lock bag. They recorded the masses of the tablet, and the bag. Then they added 50 grams of water and quickly sealed the bag. The tablet began to fizz and soon disappeared. The bag was filled with gas. If the mass of the liquid after the reaction is completed is still 50 grams, how much gas is produced?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

12. ritu obtained a distinct image of a distant tree on the screen with the of a concave mirror. to find the focal length of the mirror she has to measure the distance between: (a) mirror and the tree. (b) screen and the tree.(c) mirror and the screen. (d) mirror and tree as well as between screen and the tree.

Acarpenter is driving a 15.0-g steel nail into a board. his 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. what is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? the specific heat of steel is 448 j/kg ∙ k. a) 2.7 k b) 1.8 k c) 7.7 k d) 8.1 k e) 3.6 k