- #1
sweetpete28
- 80
- 0
Force F is applied to the rim of a uniform disk (M=3.13kg, R=.193m). The disk is mounted on a fixed frictionless axis through its center, and the force is applied at an angle β=45.8° to the radius. The disk starts at rest, and reaches frequency f = 61.1 revolutions per second after rotating through an angle θ = 609 radians.
What is the magnitude of force F?
Torque = FRsinβ
Torque = I∂
∂ = ωf - ωi / t
ωf = 2∏f = 383.9026 rad/s
ωf = θ/t; 609 rad / 383.9026 rad/s = 1.586, so t = 1.586 s
∂ = 383.9026 / 1.586 = 242.005 rad/s^2
Torque = (1/2)(MR^2)(∂)
Torque = (1/2)(3.13)(.193)^2(242.005) = 14.1076
14.1076 = F(.193)(sin 45.8)
F = 102 N
But 102 N is wrong so I guess Torque really does not = FRsinβ
Can anyone help here...cause I have no clue why or how this could be wrong...
What is the magnitude of force F?
Torque = FRsinβ
Torque = I∂
∂ = ωf - ωi / t
ωf = 2∏f = 383.9026 rad/s
ωf = θ/t; 609 rad / 383.9026 rad/s = 1.586, so t = 1.586 s
∂ = 383.9026 / 1.586 = 242.005 rad/s^2
Torque = (1/2)(MR^2)(∂)
Torque = (1/2)(3.13)(.193)^2(242.005) = 14.1076
14.1076 = F(.193)(sin 45.8)
F = 102 N
But 102 N is wrong so I guess Torque really does not = FRsinβ
Can anyone help here...cause I have no clue why or how this could be wrong...