Final answer:
To find the time t1 when the block comes back to its original equilibrium position (x=0) for the first time, we need to find the period of motion.
Step-by-step explanation:
The equation of motion for a horizontal spring oscillator is given by a(t) = -k/m * x(t), where a(t) is the acceleration, k is the spring constant, m is the mass, and x(t) is the displacement. To find the time t1 when the block comes back to its original equilibrium position (x=0) for the first time, we need to find the period of motion.
The period T of the motion is given by T = 2π√(m/k). Since the block is pulled to the right a distance A beyond the equilibrium position, it will take half a period of time to reach x = 0 again. Therefore, t1 = T/2 = π√(m/k).