mechanics (1 Viewer)

[synthesisFR]

quick question-
ik how to do tehse but i never fully understood the thing they do in part e.
they equate the equation from part b. but like since those have different origins how would that work
like i know the distance they travel for the h equations is the same but just idk how to explain it

 

[carrotsss]

we’re integrating the RHS from 0 (ie the maximum height) to v (when it hits the ground). In this case, they’re treating the max height as 0 because you have to start again as the particle falls down since the acceleration is different, so that’s the lower limit, and because the downwards direction is positive, the upper limit of the LHS is the distance to the ground from the maximum, which is just the height

hopefully that makes sense

 

[synthesisFR]

this is what the hsc wants for vertical motion:
i havent looked at the question yet but this was for the same topic:



so then for vertical projection, if it falls down are we supposed to make a new equation or use the existing? bc the hsc prefers this.

 

[carrotsss]

it really doesn’t matter, I personally would prefer using a new equation because it reduces errors but whichever one works better for you