Answer:
the angle is changing at a rate of 0.0375 rad/s when the time is t=8 seconds
Step-by-step explanation:
since the line D that starts from the spectator and follows the plane has the following equation
D² = x² + H² , where H= altitude of the plane , x= horizontal distance
then for x=v*t , where v=speed of the plane and t=time since the plane has passed overhead , we have for the elevation angle
tan θ = x/y = v*t /H
θ = tan⁻¹ ( v*t /H)
the rate of change in the angle of the spectator's sight θ with the time is
dθ/dt = 1/1+(v*t /H)² * (v/H) = (v/H)/[1+ (v/H)²*t²]
for t=8 seconds
dθ/dt = (875 ft/s/21000 ft)/[1+ (875 ft/s/21000 ft)²*(8 s)²] = 0.0375 rad/s
therefore the angle is changing at a rate of 0.0375 rad/s when the time is t=8 seconds
9514 1404 393
Answer:
(d) A = 14.28 in², P = 14.28 in
Step-by-step explanation:
The figure is wholly contained within a 4" square, which has an area of (4 in)² = 16 in², and a perimeter of 4(4 in) = 16 in. Since the figure is smaller in area and has a shorter perimeter (the top corners are rounded, not square), both answer values must be less than 16.
The only reasonable choice is the last choice: 14.28 in², 14.28 in.
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If you want to figure this out in detail, you have the area of a rectangle that is 2 in by 4 in, and the area of a semicircle of radius 2 in. The total area is ...
A = LW +1/2πr²
A = (2 in)(4 in) + 1/2(3.14)(2 in)² = 8 in² +6.28 in²
A = 14.28 in²
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The perimeter is half that of a 4" square, plus half that of a 4" circle.
P = 1/2(4(4 in) +π(4 in)) = (2 in)(4 +π) = 2(7.14) in
P = 14.28 in
Answer:
The value of y is 14
Step-by-step explanation:
we know that
The formula to calculate the slope between two points is equal to
we have the points


substitute in the formula the given values
solve for y
Multiply by 6 both sides
<span>There
are 8 912 butterflies on one branch.
And they estimated to have 1000 times as large.
now, find the total number of the butterflies found in their site.
=> 8 912 x 1000 (because it is stated that the number of butterflies in all
is 1 000 times as large as the given number of butterflies in a one branch.)
=> Multiply 8 912 by 1 000
=> 8 912 000
Thus, the total of butterflies in their site is approximately 8 912 000</span><span>
</span>
Answer:
3) reflexive property
4) Side-Angle-Side
Step-by-step explanation: