Did you know jet fighters are sometimes powered by steam? On aircraft carriers, jet fighters are launched from the deck by means of a steam catapult, which helps accelerate the aircraft quickly enough to achieve takeoff speed in the short distance of the carrier deck. The necessary takeoff speed for a modern carrier based fighter is 8 0 m/s and the length of the steam catapult on a carrier deck is around 9 5 m . If the acceleration of the jet from rest is constant, what is the minimum acceleration the catapult must provide during takeoff in m/s 2 ?
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What is v^2 (if that is a v) and what is u^2 (if that is a u)? Are these the final and initial velocity? Please help.
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you're right. v stands for final velocity and u stands for initial velocity. v^2 and u^2 means the square of v and u respectively.
v^2 - u^2 = 2as
v=final velocity = 80 m/s
u=initial velocity = 0 m/s
s=distance=95m
Therefore, a=acceleration=(6400/(2*95))=3200/95
but I know that a = (V2 - V1)/(t2 - t1) what happened to this equation
what is the u Mean ??? v is for Vector right ! and A is for Acceleration of the object !
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V is for Velocity and A is for acceleration that's right.
Work done=Change in ke!.........mar=1/2mv^2....
why doesnt velocity=displacement/time applicable?i get the time from this equation and divide it to velocity and get wrong
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You mean v = t s . But that’s only applicable when there’s no acceleration,you get it ?
a stone is tied to a string and is rotated horizonally, name the force that provides the centripetal force t the string
d = u t + 2 1 a t 2
v = u + a t
Plugging in numbers we get
9 5 = 2 1 a t 2
1 9 0 = a t 2
8 0 = a t
Solving the system we get t = 2 . 3 7 5
Plugging it back into the equations gives us 8 0 = a ( 2 . 3 7 5 )
a = 2 . 3 7 5 8 0 = 3 3 . 6 8
By third law of motion we know - v²-u²=2 a s.
So the final velocity of the aircraft to be attained is 80m/s. And it starts from rest so initial velocity is zero.The distance to be travelled is 95m.Onapplying this equation we get that the acceleration required must be33.68m/s²
Acceleration is uniform, so, we can use the equation of uniform accelerated bodies, i.e
2
a
S
=
(
v
f
)
2
−
(
v
i
)
2
,
Where,
a
is the uniform acceleration (which is required in this problem)
v
f
is the final velocity which is attained by the body (in this case the necessary takeoff velocity)
v
i
is the initial velocity of the body (in this case is zero because the jet is initially at rest), and
S
is the distance covered during the motion (in this case is the length of the stream catapult)
rearranging the formula we get:
a
=
2
S
(
v
f
)
2
substituting values in the formula we have:
a
=
2
∗
9
5
8
0
2
Therefore,
a
=
3
3
.
6
8
v = 80m/s, s = 95m, a =? using relation: a = v^2 / 2 *S putting the values, we get a = 33.68
v = velocity a = acceleration What is s?
Sorry, Math is my weakness. Next to Math is Physics and Chemistry. Please help me improve.
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s stands for the distance or height.
We know that the distance is equal to the initial velocity times t, plus the integration on acceleration in terms of t which gives the velocity at each point t... We know this distance to be 95 m and the initial velocity to be 0 so...
95 = 1/2a(t^2)
We also know that a = (vf - vi)/t. The final velocity of the jet must be at least 80m/s so a = 80/t
Substituting we get...
95 = 1/2(80/t)(t^2)
190 = 80t^2/t
190 = 80t
t = 2.375
Since a = 80/t
a = 80/2.375 = 33.68m/s^2
use the v^2=u^2+2as (80)^2=u^2+2a95 a=33.68approx=34
v^2 - u^2 = 2as
v=final velocity = 80 m/s
u=initial velocity = 0 m/s
s=distance=95m
Therefore, a=acceleration=(6400/(2*95))=3200/95
as we know
v 2 = u 2 + 2 a s
here v=80m/s ; v 2 =1600 ( m / s ) 2
u=0 [time of taking off u of aircraft is fixed ]
s=95m
we get 1600\ ( m / s ) 2 = 2 a 95m
a= 33.68
using the third equation of motion ie is squareof final velocity is equal to intial velocity square plus 2as where a is the accelaration and s is the distance to be covered ...now substitute and find the answer
Given that-> initial velocity u=0, final velocity=80, distance x=95 using v^{2} = u^{2} + 2ax a= \frac{v^{2} - u^{2}}{2x} on put the values a=33.6842105263158m/s^{2}
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By the Equation of motion, v 2 = u 2 + 2 a s
where v is the final velocity , u is the initial velocity , a is the acceleration and s is the displacement .To get the minimum acceleration we are considering the greatest displacement that is 9 5 m . As the jet starts from rest u = 0 .
a = 2 s v 2 − u 2 ,by the equation
= 2 × 9 5 8 0 2 − 0 2
= 3 3 . 6 8 4