A wind-tunnel experimentis performed on a 1/25scale model of a supersonic aircraft. The prototype aircraft flies at 450 m/s in c
onditions where the speed of sound is 250 m/s and the air density is 0.89kg/m3. The model aircraft is tested in a wind tunnel in which the speed of sound is 280m/s and the air density is 0.56kg/m3. The drag force on the model is 100N. What speed must the flow in the wind tunnel be for dynamic similitude, and what is the drag force on the prototype?
1 answer:
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Answer:
Explanation:
Use the one-dimensional equation
Δx = where delta x is the displacement of the object, v0 is the velocity of the object, a is the pull of gravity, and t is the time in seconds. That's our unknown.
Δx = -2 (negative because where it ends up is lower than the point at which it started),
, and
a = -9.8
Filling in:
and simplified a bit:
this should look hauntingly familiar (a quadratic, which is parabolic motion...very important in physics!!). We begin by getting everything on one side of the equals sign and solving for t by factoring:
(the 0 is also indicative of the object landing on the ground! Isn't this a beautiful thing, how it all just works so perfectly together?)
When you factor this however your math/physics teacher has you factoring you will get that
t = 1.3 sec and t = -.31 sec
Since we all know that time can NEVER be negative, it takes the ball 1.3 sec to hit the ground from a height of 2 m if it is rolling off the shelf at 5 m/s.
Answer:
a) By => a= 70291.70.
(b)By => t= 1.58 ms.
(c)By => H = 46045.92 m.
Explanation:
a) By
(b)By
(c)By