The given figure represents the variation of acceleration with time for a particle starting from rest at x=0. Let's analyze the given information in detail.

Initial conditions:
- The particle starts from rest at x=0, which means its initial velocity is zero.
- At t=0, the acceleration of the particle is 5 m/s^2.

Variation of acceleration with time:
- The graph shows that the acceleration initially increases with time, reaches a maximum value, and then decreases gradually.
- The maximum value of acceleration is not mentioned in the question, so let's assume it to be A_max.

Analysis:
1. Phase 1: Increasing acceleration (0 < t="" />< />
- During this phase, the particle experiences an increasing acceleration, starting from zero at t=0.
- The increase in acceleration indicates that there is a net force acting on the particle, which causes it to gain speed.
- As the acceleration increases, the particle's velocity also increases.

2. Phase 2: Constant acceleration (t1 < t="" />< />
- At t=t1, the acceleration reaches its maximum value A_max. From that point onwards, the acceleration remains constant until t=t2.
- During this phase, the particle continues to gain speed at a constant rate.
- The constant acceleration implies that the net force acting on the particle is also constant.

3. Phase 3: Decreasing acceleration (t2 < t="" />< />
- After reaching t=t2, the acceleration starts to decrease gradually.
- This decrease in acceleration indicates that the net force acting on the particle is reducing.
- As the acceleration decreases, the particle's velocity continues to increase, but at a decreasing rate.

4. Phase 4: Constant velocity (t > t3):
- At t=t3, the acceleration becomes zero, which means the net force acting on the particle is zero.
- When the net force is zero, the particle achieves a constant velocity.
- The particle continues to move with this constant velocity until any other force acts upon it.

Conclusion:
- The given graph represents the variation of acceleration with time for a particle starting from rest at x=0.
- Initially, the particle experiences an increasing acceleration, then a constant acceleration, followed by a decreasing acceleration.
- After reaching a certain time, the particle achieves a constant velocity.