Explanation

When a rotating body decelerates uniformly from an initial angular velocity (ω₀) to zero, the average angular velocity is ω₀/2.

Since the disc was initially rotating at 1 revolution per second, the initial angular velocity (ω₀) is 1 rev/s.

The total number of revolutions (n) is given by:

n = (ω₀/2) * t

where t is the time taken to come to rest.

Since the deceleration is uniform, the time taken to come to rest is:

t = ω₀ / α

where α is the angular deceleration.

Substituting this value of t in the equation for n, we get:

n = (ω₀/2) * (ω₀ / α)

= (1/2) * (1)

= 1