The car starts to make a uniform acceleration linear motion with the acceleration of A1 from static, and after a period of time, makes a uniform motion with the acceleration of A2. The time of the whole process is t. please write down the detailed process of solving the problem. It is also useful to discuss the size of A2 instead of the direction?

The car starts to make a uniform acceleration linear motion with the acceleration of A1 from static, and after a period of time, makes a uniform motion with the acceleration of A2. The time of the whole process is t. please write down the detailed process of solving the problem. It is also useful to discuss the size of A2 instead of the direction?

There is no need to discuss it
When the total time is fixed, it's OK,
The whole process is from the beginning to the end
The time to change the acceleration can be calculated. At that point, the velocity is the same. Let T1 be the moment
a1*t1=a2*(t-t1)
t1=a2*t/(a1+a2)
Total displacement S = 0.5a1t1 ^ 2 + 0.5a2 (t-t1) ^ 2