A3.5 kg block is pushed along a horizontal floor by a force f? of magnitude 15 n at an angle ? =40° with the horizontal (fig. 6.8). the coefficient of kinetic friction between the block and the floor is 0.25 . calculate the magnitudes of (a) the frictional force on the block from the floor and (b) the block's acceleration.

Abag of potato chips contains 2.00 l of air when it is sealed at sea level at a pressure of 1.00 atm and a temperature of 20.0 deg c. what will be the volume of the air in the bag if you take it with you, still sealed, to the mountains where the temperature is 7.00 deg c and atmospheric pressure is 70.0 kpa? assume that the bag behaves like a balloon and that the air in the bag is in thermal equilibrium with the outside air.