Acceleration time graph for bouncing object

I’m really confused about the shape of the accelerator time graph shown below. I’ve asked my teacher but it was no help…
Could someone please help

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(edited 1 month ago)

Reply 1

mqb2766

Original post by Nat4695

I’m really confused about the shape of the accelerator time graph shown below. I’ve asked my teacher but it was no help…
Could someone please help

Attachment not found

The brief "spikes" are when the ball bounces, otherwise the acceleration is -g as youd expect. The bounces are a short duration event (so thin spikes) and the average acceleration during the bounce is positive as a negative (downwards) velocity becomes positive (upwards). The average acceleration of successive bounces decreases as the system loses energy on each bounce due to the ball deformation during the bounce.

Note the graph seems to be quite rough as Id have expected a "better balance" between the +ive area during a bounce and the -ive area during the parabolic free flight as the area represents the change in velocity over that time (equivalent to the impulse when its mutipled by mass). The +ive area spikes look a bit small to be realistic.

(edited 1 month ago)

Reply 2

Nat4695

that is much clearer now thanks! and i agree, the diagrams are sketches from SME and a past paper tho, but i suppose the gist is to understand the type of graph that would be made even if not fully accurate.