an object of mass m is given an initial downward velocity,Vo,and allowed to fall under influence of gravity. Assuming the gravitational force is constant and the force due to the air resistance is proportional to the velocity of the object.
determine the mathematical model for this object~~~ =.="

Question

anonymous · Answer

mg - Cv = mv'

anonymous · Answer

which is first order differential equation

anonymous · Answer

dear coolsector, can u explain it a lil bit~~
coz it quite hard for me to understand it~~ =.="

anonymous · Answer

ok, when the object is falling down
there is force of gravity acting downwards, the air resistance will act upwards (against the direction of the velocity) and it will result in acceleration downward

taking the downward direction as positive we will get :


mg - force of gravity
-cv - air resistance (where v is the velocity)

mv' -> its actually ma where a is acceleration but v' is actually acceleration

put all together 
mg - Cv = mv'

anonymous · Answer

oooo~~~
thankz~~~ =)

anonymous · Answer

may i interrupt..i just want to known did  force of gravity can be negative????