A 180-kg merry-go-round in the shape of a uniform, solid, horizontal disk of radius 1.50 m is set in motion by wrapping a rope about the rim of the disk and pulling on the rope. What constant force would have to be exerted on the rope to bring the merry-go-round from rest to an angular speed of 0.400 rev/s in 2.00 s

Respuesta :

Answer:

The force acting on the rope is 211.95 N.

Explanation:

Given that,

Mass of merry-go-round, m = 180 kg

Radius of merry-go-round, r = 1.5 m

Initial angular speed is 0 it was at rest

Final angular speed, [tex]\omega_f=0.4\ rev/s=3.14\ rad/s[/tex]

Time, t = 2 s

When it moves in circular path, the torque acting on it is given by :

[tex]\tau=F\times r=I\alpha \\\\F=\dfrac{I\alpha}{r}\\\\F=\dfrac{mr^2\omega_f}{2rt}\\\\F=\dfrac{180\times (1.5)^2\times 3.14}{2\times 1.5\times 2}\\\\F=211.95\ N[/tex]

So, the force acting on the rope is 211.95 N.