Step-by-step explanation:
It is given that,
Angular frequency,

Maximum displacement, A = 0.5 m at t = 0 s
We need to find the time at which it reaches its maximum speed. Firstly, we will find the maximum velocity of the object that is exhibiting SHM.


............(1)
Acceleration of the object,


...............(2)
Using first equation of motion we can calculate the time taken to reach maximum speed.



t = 0.25 s
So, the object will take 0.25 seconds to reach its maximum speed. Hence, this is the required solution.