Answer:
Step-by-step explanation:
Angular speed of the motion ( SHM )
ω = √k/m 
= √(580/.23 )
= 50.20 radian /s 
a ) Rate of doing work 
= power = force x velocity
At the equilibrium position force becomes zero so 
rate of doing work is zero. 
b ) 
If a be the amplitude 
1/2 k a² = 170
a = .7655 m 
kinetic energy at equilibrium = 1/ 2 m v₀²
1/ 2 m v₀² = 170 
.5 x 23 v₀² = 170 
v₀ = 3.84 m /s which is the maximum velocity.
Given x = .66 where rate of doing work is to be calculated. 
Force at x = ω² x 
= 50.20² x .66 =
= 1663.22 N 
Velocity v = v₀ √( a² - x² )
= 3.84 √( .7655² - .66 )
= 3.84 x .387
= 1.486 m/s 
power = force x velocity 
= 1663.22 x 1.486 
= 2471.55 W .