A yoyo with a mass of m = 150 g is released from rest as shown in the figure.

The inner radius of the yoyo is r = 2.14 cm, and the outer radius is R = 4.00 cm, and the moment of inertia about the axis perpendicular to the plane of the yoyo and passing through the center of mass is I[tex]_{cm}[/tex] = 1.01×10-4 kgm2.

1. Determine the linear acceleration of the yoyo.

2. Determine the angular acceleration of the yoyo.

3. What is the weight of the yoyo? (Hint: It's not 150 g)

4. What is the tension in the rope?

5. If a 1.27 m long section of the rope unwinds from the yoyo, then what will be the angular speed of the yoyo?

A yoyo with a mass of m 150 g is released from rest as shown in the figureThe inner radius of the yoyo is r 214 cm and the outer radius is R 400 cm and the mome class=

Respuesta :

(1) The linear acceleration of the yoyo is 3.21 m/s².

(2) The angular acceleration of the yoyo is 80.25 rad/s²

(3) The  weight of the yoyo is 1.47 N

(4) The tension in the rope is 1.47 N.

(5) The angular speed of the yoyo is 71.385 rad/s.

Linear acceleration of the yoyo

The linear acceleration of the yoyo is calculated by applying the principle of conservation of angular momentum.

∑τ = Iα

rT - Rf = Iα

where;

  • I is moment of inertia
  • α is angular acceleration
  • T is tension in the rope
  • r is inner radius
  • R is outer radius
  • f is frictional force

rT - Rf = Iα  ----- (1)

T - f = Ma  -------- (2)

a = Rα

where;

  • a is the linear acceleration of the yoyo

Torque equation for frictional force;

[tex]f = (\frac{r}{R} T) - (\frac{I}{R^2} )a[/tex]

solve (1) and (2)

[tex]a = \frac{TR(R - r)}{I + MR^2}[/tex]

since the yoyo is pulled in vertical direction, T = mg [tex]a = \frac{mgR(R - r)}{I + MR^2} \\\\a = \frac{(0.15\times 9.8 \times 0.04)(0.04 - 0.0214)}{1.01 \times 10^{-4} \ + \ (0.15 \times 0.04^2)} \\\\a = 3.21 \ m/s^2[/tex]

Angular acceleration of the yoyo

α = a/R

α = 3.21/0.04

α = 80.25 rad/s²

Weight of the yoyo

W = mg

W = 0.15 x 9.8 = 1.47 N

Tension in the rope

T = mg = 1.47 N

Angular speed of the yoyo

v² = u² + 2as

v² = 0 + 2(3.21)(1.27)

v² = 8.1534

v = √8.1534

v = 2.855 m/s

ω = v/R

ω = 2.855/0.04

ω = 71.385 rad/s

Learn more about angular speed here: https://brainly.com/question/6860269

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