1 atm of pressure corresponds to 760 mmHg. Therefore, we can set a simple proportion to find how many atmospheres of pressure correspond to 633 mmHg, in the following way:

And if we solve this proportion, we find the pressure in atmospheres:
Answer:
Using an object of less mass can reduce the energy lost due to friction.
Explanation:
let the mass of the object be M.
acceleration due to gravity be g, coefficient of kinetic friction between object and slider be
, angle between horizntal and slider be ∅ and distance slided by the object be d.
work done by friction of the ramp will be the energy lost by ramp due to friction.
work done = force×displacement
force =
×M×g×cos∅
displacement= d
therefore work done =
×M×g×cos∅×d
therefore on decreasing the mass M we can see that work done by friction decreases so the energy lost due to friction also decreases.
Because the actual package isn't moving so the gravitational potential energy stays the same. kinetic energy is gained through motion of the object not the motion of the surroundings of the object so
unless the package is falling out of a window its losing gravitational potential energy and gaining kinetic energy. hope this helps :-)