An object of a mass 1.50 kg is suspended from a rough pulley of a radius 30.0 cm by light stirring as shown in Figure 1. This pulley has a moment of inertia 0.030 kg m² about the axis of the pulley. The object is released from rest and the pulley rotates without encountering frictional force. Assume that the string does not slip on the pulley, Determine

a) the angular acceleration of the pulley
b) the tension in the string​

An object of a mass 150 kg is suspended from a rough pulley of a radius 300 cm by light stirring as shown in Figure 1 This pulley has a moment of inertia 0030 k class=

Respuesta :

Newton's second law allows us to find the results for the tension of the rope and the angular acceleration of the body are  

      a) The angular acceleration is α = 26.7 rad / s²

      b) The tension of the rope T = 2.67 N

Given parameters

  • The mass of the block m = 1.50 kg
  • The radius of the pulley R = 0.30 m
  • The moment of inertia I = 0.030 kg m²

To find

  • Angular acceleration
  • The tension of the rope

Newton's second law indicates that the net force is proportional to the product of the mass and the acceleration of the bodies

          ∑ F = m a

Where the bold letters indicate vectors, F is the external forces, m the mass and the acceleration of the body

A free body diagram is a diagram of the forces without the details of the bodies, in the attached we see a free body diagram of the system

Let's apply Newton's second law to the block

                     W - T = m a

Body weight is

                     W = mg

Let's substitute

                    mg - T = ma                  (1)

The pulley is a body that is in rotational motion so we use Newton's second law for rotation

           Σ τ = I α  

Where τ is the torque, I the moment of inertia and α the angular acceleration

             

In this case the reference system is located at the turning point  

            T R = I α

            T = [tex]\frac{I \alpha }{R}[/tex]  

Linear and angular variables are related

            a = α R

We substitute in equation 1 and write the system of equations

            mg - T = m α R

                    T = [tex]\frac{I \alpha }{R}[/tex]

We resolve

              mg = α  (m R + I / R)

             α = [tex]\frac{g}{R + \frac{I}{mR} }[/tex]  

We calculate

            α = [tex]\frac{ 9.8}{ 0.30+\frac{0.030}{1.50 \ 0.30} }[/tex]  

            α = 26.7 rad / s²

Let's calculate the tension of the rope

           T = [tex]\frac{I \alpha }{R}[/tex]  

           T = [tex]\frac{0.030 \ 26.7 }{0.30}[/tex]

           T = 2.67 N

In conclusion with Newton's second law we can find the results for the tension of the rope and the angular acceleration of the body are  

      a) The angular acceleration is alpha = 26.7 rad / s²

      b) The tension of the rope T = 2.67 N

Learn more here:  brainly.com/question/12515285

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