A particle thrown up vertically reaches its highest point in time (t) , and returns to the ground in further time (t2). the air resistance exerts a constant force on the particle opposite to its direction of motion. then???

Question

anonymous · Answer

it is in two dimensional motion

anonymous · Answer

how is the air ristance constant, its a function of velocity here which is a variable, as F(air resistance)=$$1/2C \rho Av ^{2}$$ , and the direction of air resistive force is opposite to that of direction of motion

So in Case 1

When particle is thrown up vertically it is opposed by two forces F=gravity+Air resistance

so it decelerates fast , hence it takes less time t to reach maximum height

But , In Case 2

When it falls down, gravity acts downwards as before but air resistance acts upwards opposite to the direction of motion , so F=gravity-air resistance, so it accelerates slowly, therefore it takes more time t2 to reach the bottom

If we take air resistance to be constant for simplicity, then

by direct analysis we conclude t2 is greater than t

anonymous · Answer

thanks

anonymous · Answer

Welcome :D