If a body moves through a liquid or a gas then the fluid applies a force on the body which is called drag force. Direction of the drag force is always opposite to the motion of the body relative to the fluid. At low speeds of the body, drag force ( $F_P$) is directly proportional to the speed. 
$F_P=kv$ 
When k is a proportionally constant and it depends upon the dimension of the body moving in air at relatively high speeds, the drag force applied by air on the body is proportional to  $v^2$  instead of v. 
$F_D=k_1{v}^2$ 
Where this proportionally constant K can be given by 
$k_1=\rho CA$
Where  $\rho$  is the density of air 
C is another constant giving the drag property of air 
A is area of cross-section of the body
 Consider a case an object of mass m is released from a height h and it falls under gravity. As it’s speed  increases the drag force starts increasing on the object. Due to this at some instant, the object attains equilibrium. The speed attained by the body at this instant is called “terminal speed" of the body.
Assume that the drag force applied by air on the body follows the relations $F_D=kv$ , neglect the force of buoyancy applied by air on the body then answer the following questions.