A certain airplane has a speed of 290.0 km/h and is diving at an angle of 30.0°
below the horizontal when the pilot releases a radar decoy (Fig. 4-33). The
horizontal distance between the release point and the point where the decoy
strikes the ground is d = 700 m. (a) How long is the decoy in the air? (b) How high
was the release point?
Answers
Answer:
Find the volume bounded by xy plane, x²+y²=1 the cylinders and the plane 2x+3y+4z=12
Answer:
We adopt the positive direction choices used in the textbook so that equations such as
Eq. are directly applicable. The coordinate origin is at ground level directly below
the release point. We write theta0=–30.0° since the angle shown in the figure is measured
clockwise from horizontal. We note that the initial speed of the decoy is the plane’s speed
at the moment of release: v0=290km/h, which we convert to SI units=(290)(1000/3600)
= 80.6 m/s.$$
(a) We use Eq. to solve for the time:
Δx=(v0cosθ0)t⇒t=(80.6m/s)cos(−30.00)700m=10.0s.
(b) And we use Eq. 4-22 to solve for the initial height y0:
y−y0=(v0sinθ0)t−21gt2⇒0−y0=(−40.3m/s)(10.0s)−21(9.80/s2)(10.0s2)
which yields y0=897m.
Explanation: