Velocity, acceleration, and position graphs

[Porcelain]

I have the answers, but I don't know how to get them.

The starting graph is a position-time graph of a basketball being thrown straight up into the air.
From that graph i have to find an acceleration-time graph, and a velocity-time graph.

Can someone explain to me the acceleration-time graph? why is it a constant negative line, if the graph of the position graph first goes up then down?

I think I understand how the velocity-time graph works with this.


My next question wants a graph of position vs. time, and a graph of velocity vs. time for an object moving with a constant negative acceleration.
again i have the answers, but I really don't know how to get to them.
thanks in advance for the explanations :)

 

[ideasrule]

The acceleration-time graph is a line, which means acceleration remains constant. That's how gravity works; all objects, regardless of mass, fall at an acceleration of 9.8 m/s^2 down.

For your second question, try writing out the object's velocity in an equation; ditto for its position. v=at, and d=?

 

[pgardn]

The acceleration-time graph is a line, which means acceleration remains constant. That's how gravity works; all objects, regardless of mass, fall at an acceleration of 9.8 m/s^2 down.

For your second question, try writing out the object's velocity in an equation; ditto for its position. v=at, and d=?

A horizontal line with a slope of zero, right?