I need help with a question concerning projectile motion and air resistance!?

Question

A particle of mass m is projected vertically upwards with intial speed U. It experiences an air resistance proportional to the square of its speed.

Find the time for the particle to reach its maximum height and find this height.

Answer 1

The question is incomplete. You need the air resistance constant of proportionality (the K in the following equation).

AirResistance = K v^2

.

Depending on K the answer varies. For example if

k =0:

The time to max height is simply

T=U/A

(using V=U+AT and setting V=0)

but if K =1000000:

The time to max height is almost 0 as the air resistance is so strong the projectile barely moves