When an object starts to move in a straight line with constant acceleration of A1, when it is in motion An object starts to move at a constant acceleration with an acceleration of A1. The motion time is T1. Number of Views: 825 reward points: 20 | solution time: 2009-10-31 00:21 | questioner: qiuri123 When an object starts to do uniform acceleration motion with acceleration A1 from rest, changes to uniform deceleration linear motion with acceleration A2 after time T1, and stops after time T2, the average velocity of the object in all time is () A.a1t1/2 B a1(t1+t2)/2 C a1ti(t1-t2)/2(t1+t2) D a2t2/2 Why is a1t1 = a2t2

When an object starts to move in a straight line with constant acceleration of A1, when it is in motion An object starts to move at a constant acceleration with an acceleration of A1. The motion time is T1. Number of Views: 825 reward points: 20 | solution time: 2009-10-31 00:21 | questioner: qiuri123 When an object starts to do uniform acceleration motion with acceleration A1 from rest, changes to uniform deceleration linear motion with acceleration A2 after time T1, and stops after time T2, the average velocity of the object in all time is () A.a1t1/2 B a1(t1+t2)/2 C a1ti(t1-t2)/2(t1+t2) D a2t2/2 Why is a1t1 = a2t2

A. Because the distance is (a1t1 ^ 2 + a2t2 ^ 2) / 2 and the time is T1 + T2, the average speed is: (a1t1 ^ 2 + a2t2 ^ 2) / 2 (T1 + T2). Because a1t1 = a2t2, we can extract from a1t1 ^ 2 + a2t2 ^ 2, a1t1 (T1 + T2) or a2t2 (T1 + T2), and then divide by 2 (T1 + T2), so we get the answer ad
Because the velocity starts from zero and returns to zero, the increasing velocity is equal to the decreasing velocity, so a1t1 = a2t2

1: What does it mean that the result is negative? 2: what is the definition of uniform velocity linear motion?
It's better to have easy to understand answers, not concepts

You first think about what is positive acceleration, that is, an object is driving with a certain acceleration leading to a higher and higher speed. The negative acceleration means that the acceleration direction is opposite to the motion direction, that is, the object is driving with a certain acceleration slower and slower until the speed is reduced to 0. If the negative acceleration still exists, it is opposite to the original direction, Start reverse motion~
For example, if the speed of a car is 20m / s and the acceleration is - 10m / s, the speed will be reduced to 10m / s in one second and 0 in two seconds. In another second, the speed will become - 10m / s, that is to say, it will start to move in the opposite direction, and so on
A uniformly variable speed line is a linear motion with constant acceleration, which can be positive or negative~
Hey, hey, come on!