A handbrake is applied to a spinning axle, initially moving counterclockwise, causing it to slow down with a constant angular acceleration of magnitude 5.40 rad/s2. Immediately after the handbrake is applied, the axle rotates through 60.4 rad during a 4.00 s time interval. What is the angular speed (in rad/s) of the axle at the end of this time interval?

Respuesta :

Answer:

ωf = 25.9 rad/s

Explanation:

The uniformly accelerated circular movement,  is a circular path movement in which the angular acceleration is constant.

We apply the equations of circular motion uniformly accelerated

θ=  ω₀*t + (1/2)*α*t² Formula (1)

ωf= ω₀ + α*t  Formula (2)

Where:

θ : angle that the body has rotated in a given time interval (rad)

α : angular acceleration (rad/s²)

t : time interval (s)

ω₀ : initial angular speed ( rad/s)

ωf : final angular speed ( rad/s)

Data

α= 5.40 rad/s2

θ= 60.4 rad

t  = 4.00 s

Calculating of the initial  angular speed of the  spinning axle:

We replace data in the formula (1):

θ=  ω₀*t + (1/2)*α*t²

60.4=  ω₀*(4) + (1/2)*(5.4)(4)²

60.4=  ω₀*(4) + 43.2

60.4 - 43.2=  ω₀*(4)

17.2 = ω₀*(4)

ω₀ = 17.2 /4

ω₀ = 4.3 rad/s

Calculating of the final angular speed of the  spinning axle:

We replace data in the formula (2):

ωf = ω₀ + α*t

ωf = 4.3 + (5.4)(4)

ωf = 25.9 rad/s