Someone please help me solve these i have been trying over a

Someone please help me solve these i have been trying over and over and can\'t seem to get it!!

Solution

2.

At any instant, mrw^2 = ma

a = rw^2

dv/dt = rw^2

dv/dr * dr/dt = rw^2

v = dr/dt

v*dv/dr = rw^2

v dv = rw^2 dr

Integrating both the sides,

v^2 /2 = (rw)^2 /2 + C

When r = 0.5, we have v = 3

Hence, 3^2 /2 = (0.5*6)^2 /2 + C

C = 0

Hence, v^2 /2 = (rw)^2 /2

or v = rw

Collar\'s velocity when r = 0.6 is v = 0.6*6 = 3.6 m/s