A disk of radius 25 cm spinning at a rate of 30 rpm slows to a stop over 3 seconds. what is the angular acceleration? b. how many radians did the disk turn while stopping?
c. how many revolutions?​

α = -π/3 rad/s², θ = 1.5π rad = 0.75 rev

Explanation:

ω₀ = 30 rev/min(2π rad/rev / 60 s/min) = π rad/s

α = (ω₁ - ω₀)/t = (0 - π)/3 = -π/3 rad/s²

θ = (ω₁² - ω₀²) / 2α = (0² - π²) / 2(-π/3) = 3π/2 rad

3π/2 rad / 2π rad/rev = 0.75 rev

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j