The slope on a distance-time graph shows a ball moving from 20 m to 40 min 1 s and from 40 m to 80 m in the next second.
which describes the ball's motion between 20 m and 80 m on the graph?
linear, acceleration
nonlinear, constant speed
linear, constant speed
nonlinear, acceleration

are their multiple choices ?

explanation:

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide