for the other screenshot
Average acceleration = change in velocity /change in time.
[a = ∆V/∆t] —this the formula.
NOTE:
u = initial velocity (velocity it started with)
v = final velocity (velocity it ended with)
t = time {the time you were given)
a = acceleration.
listing out our givens:
u =o —(the unit is m/s)
v = 40 —(the unit is also m/s)
t = 0.08 —(the unit is s) "s" means second(s).
Soo
a = 40-0 / 0.08 = 500 m/s² ( unit for velocity is m/s²)
( Remember when using the formula we subtract the initial from the final velocity.........I mean we remove the initial from final) if not you will get a negative answer or wrong answer).
also note: final velocity is always bigger in value than initial velocity EXCEPT it is in deceleration meaning for example a car that was speeding is gradually stopping then initial (the one it started with) will be bigger than the one it ended with (because as it gradually stops the speed reduces).
VELOCITY is speed in a specified direction.
you're super free to ask any questions
Good luck ✅.