pure estuary
a projectile is projected vertically upwards with speed u, 50m below ground
it reaches a point 100m above ground (x)
3 seconds later it reaches a point 220m above ground (y)
what is the initial speed the projectile is projected with.
Also, for this question how would one know wether point y lies on the left (so the max height comes after this point) OR if point y lies on the right, the max height comes before it
this is what i got so far
glass trail
this is what i got so far
Your bottom paragraph is complete yap
How is it going to reach 220m before 100m
pure estuary
i thought of doing the motion x to y
since you know the time and g = -9.8 and s = 120m
glass trail
where would you start from
S 150
U u
V v
A -9.8
T
v^2 = u^2 + 2as
v = sqrt all that
Id then use that v as the initial velocity for a suvat of displacement 120
Idk if that wokr
S 120
U sqrt(u^2 + 2g(150))
V
A -9.8
T 3
S = ut + 1/2 at^2
Sub in and arrange dor u?
pure estuary
but you have two unkowns that way
could you not find the initial velocity at X
Then that would be the final velocity when considering the motion from the start to X
glass trail
but you have two unkowns that way
could you not find the initial velocity at X
T...
No theres only one unknown
glass trail
No theres only one unknown
Show me your approach though
glass trail
S 120
U sqrt(u^2 + 2g(150))
V
A -9.8
T 3
S = ut + 1/2 at^2
Sub in and arrange d...
,w 120 = 3sqrt(u^2 + 300*9.8) -4.9(9)
rapid zephyrBOT
glass trail
,w sqrt(5209)/10 in decimal
rapid zephyrBOT
glass trail
7.2 sound reasonable
pure estuary
ok so i did
X to y since i know t = 3, s = 120, a = -9.8
I work out u of x doing s = ut + 1/2at^2
you get that u = 54.7
then you do from start to X
the displacement is 150m, a = -9.8 and you know velocity is 54.7 (final)
glass trail
7.2 sound reasonable
No it doenst actually
glass trail
ok so i did
X to y since i know t = 3, s = 120, a = -9.8
I work out u of x doin...
Oh Im so silly
I did it the other way roundp
Wai tno i subbed un wrong too
,w 120 = 3sqrt(u^2 + 300*-9.8) -4.9(9)
rapid zephyrBOT
rapid zephyrBOT
glass trail
Did you get that inaner
glass trail
It was 2 suvats
