A copper block rests 43.4 cm from the center of a steel turntable. The coefficient of static friction between block and surface is 0.318. The turntable starts from rest and rotates with a constant angular acceleration of 0.259 rad/s 2 . The acceleration of gravity is 9.8 m/s 2 . After what interval will the block start to slip on the turntable?[ Hint: Ignore the tangential component of the acceleration.] Answer in units of s.

Respuesta :

Answer:

10.3 s

Explanation:

We are given that

r=43.4 cm=[tex]\frac{43.4}{100}=0.434 m[/tex]

1 m=100 cm

Coefficient of static friction=[tex]\mu_s=0.318[/tex]

Angular acceleration=[tex]\alpha=0.259rad/s^2[/tex]

Initial angular velocity =[tex]\omega_1=0[/tex]

Acceleration of gravity=[tex]g=9.8m/s^2[/tex]

Angular acceleration=[tex]\alpha=\frac{\omega}{t}[/tex]

Using the formula

[tex]0.259t=\omega[/tex]

Force acting on block after time t=[tex]F=m\omega^2 r[/tex]

Friction force=[tex]f=\mu mg[/tex]

[tex]f=F[/tex]

[tex]\mu mg=m\omega^2 r[/tex]

[tex]\mu g=\omega^2 r[/tex]

Substitute the values

[tex]0.318\times 9.8=(0.259t)^2 r[/tex]

[tex]t^2=\frac{0.318\times 9.8}{(0.259)^2\times 0.434}[/tex]

[tex]t=\sqrt{\frac{0.318\times 9.8}{(0.259)^2\times 0.434}}[/tex]

[tex]t=10.3 s[/tex]

Hence, the block will start to slip on the turntable after 10.3 s.

The block will start to slip on the turntable after 10.3s.

What is Angular acceleration?

Thin is defined as the rate of change of angular velocity with time.

Parameters

Coefficient of static friction = 0.318

Angular acceleration =  0.259 rad/s²

Initial angular velocity = 0

Acceleration of gravity = 9.8m/s²

Angular acceleration = Angular velocity/ time

0.259t = ω

Force = mω²r

Frictional force = μmg

μmg = mω²r

Substitute the values into the equation

0.318 ₓ 9.8 =  (0.259t)²r

t² = (0.318 ₓ 9.8) / (0.259)² ₓ 0.434))

t² = 106.09

t = √106.09 = 10.3s

Read more about Angular acceleration here https://brainly.com/question/1980605