Question

48) A disc of moment of inertia 5 kg-mis acted upon
by a constant torque of 40 Nm. Starting from rest
the time taken by it (sec) acquire an angular velocity
of 24 rad/sec is on​

Answer 1

Answer:

3 seconds

Explanation:

as above in image

Answer 2

We know that tourqe is the product of moment of inertia and angular acceleration .

.) So mathematically we can write it as ,

T = I*α

Where T is the tourqe , I is the moment of inertia and α is the angular acceleration .

Now we have T = 40Nm,I = 5Kgm^2

.) Now putting values in the equation we get ,

40 = 5*α => α = 40/5

α = 8 rad/sec^2

.) Now we know that

α = ( Wf -Wi ) / t

Where , W is the angular velocity and t is the time taken .

.) Now here , Wf = 24rad/sec and Wi=0

Now we get

α = ( 24 - 0) / t

8 = 24 / t => t = 24 /8

t = 3 sec