20. use the velocity - time graphs below to answer the following question. which velocity - time graphs…

Explanation:

Step1: Recall acceleration - velocity relation

Acceleration is the slope of velocity - time graph. Constant acceleration means constant slope.

Step2: Analyze each graph

(1): Horizontal line, zero acceleration. (2): Triangular shape, constant non - zero slope in two parts (first positive then negative). (3): Straight line with negative slope, constant negative acceleration. (4): Straight line with positive slope, constant positive acceleration. (5): Two straight line segments with different slopes, non - constant acceleration. (6): Curved line, non - constant slope, non - constant acceleration.

Answer:

2, 3, 4