For an isochoric process, the volume is constant, which means the equation of state is far simpler than for the adiabatic process. namely, it is:
v = constant
as in the case above, assume we don’t have a good way to measure the volume, and rewrite this equation of state in terms of pressure and temperature.

the resistance that one surface or object encounters when moving over another.

"a lubrication system that reduces friction"

synonyms: abrasion, abrading, rubbing, chafing, grating, rasping, scraping, excoriation, grinding, gnawing, eating away, wearing away/down; more

the action of one surface or object rubbing against another.

"the friction of braking"

friction is an important force because it is a force that affects motion. this force exerted by the surface of an object when another object moves against it is the result of molecular attractions between the objects' surfaces, and works in the direction opposite to the direction of the motion.

you expect to have heat energy, electrical energy, and mechanical energy involved when you iron your clothes.  

you don't expect chemical energy to show up, and if it does, it may ruin some of your clothes.

the answer is c. natural gas because both a and b are their own forms of energy.

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts