anonymous
  • anonymous
MEDAL a bullet is fired horizontally at a velocity of 220 m/s. it strikes the ground at a distance of 511 m from where it was fired. how high above the ground was the bullet when it fired
Mathematics
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
katieb
  • katieb
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
NetherCreep333
  • NetherCreep333
Whats the question?
anonymous
  • anonymous
how high above the ground was the bullet when it fired
anonymous
  • anonymous
physics

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

amistre64
  • amistre64
start with maybe your linear equations of motion ....
amistre64
  • amistre64
if its fired straight out, there is no initial velocity up/down and there is no acceleration acting on it from side to side since gravity pulls down, not out
anonymous
  • anonymous
d=vt
amistre64
  • amistre64
good, so t = d/v what was our time?
anonymous
  • anonymous
2.3 s
amistre64
  • amistre64
how far does something drop in 2.3 seconds?
amistre64
  • amistre64
1/2 gt^2 right?
anonymous
  • anonymous
is 2.3 correct
amistre64
  • amistre64
its good enough for me, but im not the one grading it. take it to however many decimals you want to
anonymous
  • anonymous
now do we use d=vit+1/2at^2
amistre64
  • amistre64
or just let it ride at 511/220
amistre64
  • amistre64
we can yes, vi=0 in this case
amistre64
  • amistre64
it more appropriate as: vi sin(theta) t sin(0) = 0 as its shot horizontally
anonymous
  • anonymous
use vi sin(theta) t for the formula
amistre64
  • amistre64
that is a better generalization yes
amistre64
  • amistre64
\[h(t)=\frac12gt^2+v_i~t~\sin(\theta) \]
amistre64
  • amistre64
theta represent the angle of inclination from the horizontal
anonymous
  • anonymous
so what do i plug in into the equation
amistre64
  • amistre64
your values for gravity and time
anonymous
  • anonymous
what is the intial velocity is it 0
amistre64
  • amistre64
since we are shot horizontally, then the degrees above horizontal is 0 .. 211 * sin(0) is your initial velocity in the up/down directions
anonymous
  • anonymous
so it is 0
amistre64
  • amistre64
yeah :)
amistre64
  • amistre64
so height = 1/2 gt^2
anonymous
  • anonymous
h(t) = 1/2(-9.8)(2.3)^2+0(2.3)+sin(0)
amistre64
  • amistre64
h(t) = 1/2(-9.8)(2.3)^2+211(2.3) sin(0)
amistre64
  • amistre64
h(t) = 1/2(-9.8)(2.3)^2+0 h(t) = 1/2(-9.8)(2.3)^2
anonymous
  • anonymous
why 211 should be 511
amistre64
  • amistre64
hmm, should be 220 i spose but i mistyped it since i didnt feel like scrolling all the way up to verify that it was correctly inputed.
amistre64
  • amistre64
but its immaterial, that term goes to 0
amistre64
  • amistre64
the full generalization equation for distance an object falls is: \[h(t)=-\frac12gt^2+v_it~\sin(\theta )+h_i\] h(2.3) = 0, we are on the ground \[0=-\frac12g(2.3)^2+v_i(2.3)~\sin(0 )+h_i\] \[\frac12g(2.3)^2=h_i\]
anonymous
  • anonymous
g=9.8
amistre64
  • amistre64
yes, or whatever the gravity of the planet your testing it on happens to be :)
anonymous
  • anonymous
25.92
anonymous
  • anonymous
i mean -25.92
amistre64
  • amistre64
and the dimensions is?
anonymous
  • anonymous
horizontal
amistre64
  • amistre64
no, initial height for this will be positive. you werent below ground to start with and it floated upwards ...
amistre64
  • amistre64
dimensions refered to feet, meters, yards, kilometers, etc ...
anonymous
  • anonymous
25.92 meters
amistre64
  • amistre64
good
anonymous
  • anonymous
is that the final answer
amistre64
  • amistre64
what is it we were looking for?
anonymous
  • anonymous
how high above the ground was the bullet when it fired
amistre64
  • amistre64
and did we find that?
anonymous
  • anonymous
i think so but not sure
amistre64
  • amistre64
h = 1/2 gt^2 so yeah, we found the h
anonymous
  • anonymous
can i ask another question
amistre64
  • amistre64
sure
anonymous
  • anonymous
A ball is thrown horizontally with an initial velocity of 20.0 meters per second from the top of a tower 60.0 high. What is the approximate total time required for the ball to reach the ground.
amistre64
  • amistre64
what was our generalization of finding height?
anonymous
  • anonymous
height equal 25.92
amistre64
  • amistre64
no, that was a specific case, not the general formula that i posted.
anonymous
  • anonymous
im on the next question
amistre64
  • amistre64
the great thing about generalizations, is that they work regardless of the question that you are on .. you simply reuse them with the new specifics.
anonymous
  • anonymous
d=vit+1/2at^2
amistre64
  • amistre64
almost, but then vi might confuse people if they dont understand that it pertains only to the up/down direction ..... hence the sin(theta)
anonymous
  • anonymous
so d=sin(theta) +1/2at^2
amistre64
  • amistre64
no, we dont eliminate the rest of it in favor of sin(theta) the forces involved are this: |dw:1446770512248:dw| vi is important, and so is sin(theta). sin(theta) tells us how much of the initial velocity is imparted up/down
amistre64
  • amistre64
how many degrees from teh horizontal are we?
anonymous
  • anonymous
60
anonymous
  • anonymous
or 20
amistre64
  • amistre64
if its thrown horizontally, then we are zero degrees from the horizontal ...
amistre64
  • amistre64
"A ball is thrown horizontally" it is zero degrees from the horizontal right?
amistre64
  • amistre64
h = vi t sin(0) + 1/2 at^2 h = 1/2 at^2 rearrange this to solve for t
anonymous
  • anonymous
t=1/2a^2
amistre64
  • amistre64
not quite ... multiply by 2, divide by a, and sqrt
amistre64
  • amistre64
t = sqrt(2h/a)
anonymous
  • anonymous
what is the height
amistre64
  • amistre64
its defined in your problem ...
anonymous
  • anonymous
so 60
amistre64
  • amistre64
yes, is that meters?
anonymous
  • anonymous
t=sqrt(2(60))/9.8
amistre64
  • amistre64
sqrt it all. \[t=\sqrt{\frac{2(60)}{9.8}}\]
anonymous
  • anonymous
so 3.50
amistre64
  • amistre64
sounds reasonable to me
anonymous
  • anonymous
the correct answer is 3.50 sec
amistre64
  • amistre64
yes
amistre64
  • amistre64
good luck :)
anonymous
  • anonymous
one more question

Looking for something else?

Not the answer you are looking for? Search for more explanations.