Explanation:
It is given that,
Angular frequency, [tex]\omega=4\ s^{-1}[/tex]
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.
[tex]v_{max}=A\times \omega[/tex]
[tex]v_{max}=0.5\times 4[/tex]
[tex]v_{max}=2\ m/s[/tex]............(1)
Acceleration of the object, [tex]a=\omega^2A[/tex]
[tex]a=4^2\times 0.5[/tex]
[tex]a=8\ m/s^2[/tex]...............(2)
Using first equation of motion we can calculate the time taken to reach maximum speed.
[tex]v=u+at[/tex]
[tex]t=\dfrac{v-u}{a}[/tex]
[tex]t=\dfrac{2-0}{8}[/tex]
t = 0.25 s
So, the object will take 0.25 seconds to reach its maximum speed. Hence, this is the required solution.