Physics
posted by Ashley .
A 190kg merrygoround 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 merrygoround from rest to an angular speed of 0.700 rev/s in 2.00 s? (State the magnitude of the force.)

Physics 
Jennifer
F*r = I * a
Where F is the force on the merrygoround, r is the radius, I is the moment of inertia of the merrygoround, and a is the angular acceleration
for a solid, horizontal disk, the moment of inertia is: 1/2*m*r^2
F*r = 1/2*m*r^2*a
F = 1/2*m*r*a
w = w0 + a*t
where w is the angular speed, t is time, w0 is the initial angular speed
0.7 rev / s *(2*pi radians/rev) = 4.3 radians/s
4.3 = a*2
a = 2.2 rad/s^2
Plug this into the above equation to solve for F 
Physics 
yesi
wrong
Respond to this Question
Similar Questions

physics
A 175 kg merrygoround 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 … 
physics
A horizontal 791 N merrygoround is a solid disk of radius 1.48 m, started from rest by a constant horizontal force of 50.0 N applied tangentially to the edge of the disk. Find the kinetic energy of the disk after 3.01 s. I am having … 
Physics
Figure 1042 shows a uniform disk that can rotate around its center like a merrygoround. The disk has a radius of 2.00 cm and a mass of 20.0 grams and is initially at rest. Starting at time t = 0, two forces are to be applied tangentially … 
physics 101
A solid uniform disk of mass 21kg and radius 85cm is at rest flat on a frictionless surface. A string is wrapped around the rim of the disk and constant force of 35N is applied to the string, which does not slip on the rim, in the … 
Physics
A 190kg merrygoround 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 … 
PHYSICS
A 190kg merrygoround 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 … 
physics
A 346 kg merrygoround in the shape of a horizontal disk with a radius of 1.7 m is set in motion by wrapping a rope about the rim of the disk and pulling on the rope. How large a torque would have to be exerted to bring the merrygoround … 
Physics
A uniform disk with mass 6 kg and radius 1.8 m is pivoted at its center about a horizontal, frictionless axle that is stationary. The disk is initially at rest, and then a constant force 31.5N is applied to the rim of the disk. The … 
Physics
A uniform disk of radius 0.485 m and unknown mass is constrained to rotate about a perpendicular axis through its center. A ring with same mass as the disk\'s is attached around the disk\'s rim. A tangential force of 0.247 N applied … 
Physic question help
A uniform disk with mass 9.6 kg and radius 2.7 m is pivoted at its center about a horizontal, frictionless axle that is stationary. The disk is initially at rest, and then a constant force 31.5N is applied to the rim of the disk. The …