Question

26. Starting from rest the fly wheel of a motor attains an angular velocity of 60
ad/s in 15 seconds. The angular acceleration attained by the wheel is
rad/s.
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Answer 1

Given:-

→ A fly wheel starts from rest.

→ Velocity attained by the flywheel = 60 rad/s

→ Time taken = 15 seconds

To find:-

→ Angular acceleration of the flywheel.

Solution:-

• Since the fly wheel starts from rest, so it's initial angular velocity will be zero.

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Now from the 1st equation of motion, we have :-

ω₁ = ω₂ + at

Where :-

• ω₁ is the final angular velocity.

• ω₂ is the initial angular velocity

• a is angular acceleration.

• t is time.

Substituting values, we get :-

⇒ 60 = 0 + a(15)

⇒ 60 = 15a

⇒ a = 60/15

⇒ a = 4 rad/s²

Thus, angular acceleration attained by the fly wheel is 4 rad/s² .

Answer 2

Answer:

Angular acceleration attained by the fly wheel is 4 rad/s² .

Explanation:

Given :-

Starting from rest, the fly wheel of a motor attains an angular velocity of 60 rad/sec in 15 seconds.

Angular velocity = 60 rad/sec

Time taken = 15 sec

To find :-

Angular acceleration attained by the the wheel

Solution :-

As the fly is at rest, it started from rest hence the angular velocity will be 0.

Then, from equation of motion,

v = u + at

Here,

ω₁ = ω₂ + at

Where,

v (ω₁) = Final velocity (Final angular velocity)

u (ω₂) = Initial velocity (Initial angular velocity)

a (a) = Acceleration (Angular acceleration)

t (t) = time

Substituting we get,

60 = 0 + a(15)

60 = 0 + 15a

60 = 15a

a = 60/15

a = 4

∴ Angular acceleration (a) is 4 rad/s².

The angular acceleration of a rotating object is the rate at which the angular velocity changes with respect to the time.