Calculating speed from a-t graph!? (1 Viewer)

[WildestDreams]

Is it possible to calculate final speed from an acceleration time graph? IF so, how would you do that?


*Need to calculate speed of jet ski and car.

 

[Nailgun]

edit: jokes this is wrong, i forgot about the dodgy calculus physics method
gimme a sec

 

[Nailgun]

edit: jokes this is wrong, i forgot about the dodgy calculus physics method
gimme a sec

Ok lol I got the same answer both ways
whats the answer in the textbook?

for the car

 

[WildestDreams]

If it helps, the answer is 21ms-1 for the Jet ski and the answer is 33ms-1. I'm confused how they got that answer though :/

 

[Nailgun]

If it helps, the answer is 21ms-1 for the Jet ski and the answer is 33ms-1. I'm confused how they got that answer though :/

Yeah I used calculus to recheck the answer, and I still come up with 35ms-1 so idk haahah. Maybe InteGrand can shed some light on it
Using the above method still gets you 21ms-1 for the jet ski though

 

[InteGrand]

 

[WildestDreams]

Oh okay! Thanks for your help
Wait, where did you get the 5 and 3 from?

 

[Nailgun]

Jokes I didn't see that there was a bend in the car line, dw I got it.

Basically, you can do a kind of pseudo integration to calculate the the change in velocity by calculating area under the graph
If you split up the area into parts, you have a 2 triangles and a rectangle
adding them up together you get 29ms-1
then add 5 because it is the change in velocity
=33ms-1

It didn't matter for the jetski because there was a uniform change in acceleration (so straight line)

 

[Nailgun]

Just find the area under the curve for each vehicle. This gives us the change in velocity for each vehicle. Adding this to the initial velocity gives us the final velocity. We don't need calculus to find the areas because they are just triangles (the curves are made up of straight lines only, so use formulas like half base height).

Yeah lol this was what you were meant to do

 

[WildestDreams]

OH okay that makes so much more sense now!
Thank you!!

 

[WildestDreams]

The areas meant to be 28 lol

 

[Nailgun]

The areas meant to be 28 lol

..awks ahah

 

[anomalousdecay]

ignore

http://www.subaru-global.com/assets/files/32/d606f026c44dd092190c52ed0236f2.jpg

 

[anomalousdecay]

ignore pls

http://www.formula1-dictionary.net/Big/pullrod_pushrod_comparison_big.jpg