Step 1: Given displacement equation.
The displacement of the particle is given by:
\[
x = 5 \sin\left(\frac{\pi t}{3}\right) \, \text{m}
\]
where \( t \) is time.
Step 2: Find velocity equation.
The velocity \( v \) is the derivative of displacement with respect to time:
\[
v = \frac{dx}{dt} = 5 \cdot \frac{\pi}{3} \cdot \cos\left(\frac{\pi t}{3}\right)
\]
Step 3: Calculate velocity at \( t = 1 \, \text{s} \).
Substitute \( t = 1 \) second into the velocity equation:
\[
v = 5 \cdot \frac{\pi}{3} \cdot \cos\left(\frac{\pi}{3}\right)
\]
Since \( \cos\left(\frac{\pi}{3}\right) = \frac{1}{2} \), we get:
\[
v = \frac{5\pi}{3} \, \text{m/s}
\]
Step 4: Conclusion.
The velocity of the particle after 1 second is \( \frac{5\pi}{3} \, \text{m/s} \).