A robot standing on a cliff shoots a ball upwards with an initial speed of 30 m/s. What is the height of the cliff given that th
e ball reaches the bottom of the cliff 8 s after the shoot? (Take g = 10 m/s^2 and the height of the robot is negligible.)
A 25 m
B 45 m
C 80 m
D 145 m
A 25 m
B 45 m
C 80 m
D 145 m
1 answer:
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Answer:
distance from speaker is 17.87 m
Explanation:
given data
distance from loudspeaker = 2.5 m
distance between loudspeaker = 3.0 m
room temperature = 20c
wavelength f = 686Hz
to find out
what distances from the speaker
solution
we know sound velocity c = 331.5 + 0.6 × 20c = 343.5
so wavelength of sound λ = c / f
wavelength = 343.5 / 686 = 0.5 m
when the difference in distance of speaker destructive interference will be
d = λ/2 × (2n-1)
for n = 1, 2 3 4 ..
d = 0.5/2 × (2n-1)
d = 0.250 , 0.75 , 1.25 , 1.750............ for n = 1, 2 3 .............
so
for d = 0.250
side of triangle by hypotenuse of triangle are
= 0.250
0.5 x1 = 7.6875
x1 = 15.375 m
for d = 0.75
side of triangle by hypotenuse of triangle are
= 0.75
1.5 x2 = 4.6875
x2 = 3.125 m
for d = 1.250
side of triangle by hypotenuse of triangle are
= 1.250
2.5 x2 = 1.1875
x3 = 0.475 m
for d = 1.750
x4 will be negative so we stop here
so the distance from speaker here is given below
distance = 2.5 + x
here x = 0.475 , 3.125 and 15.375 so
distance 1 = 2.5 + 0.475 = 2.975 m
distance 2 = 2.5 + 3.125 = 5.625 m
distance 3 = 2.5 + 15.375 = 17.875 m
final distance from speaker is 17.87 m
The power in horsepower is 40.1 hp
Explanation:
We start by calculating the work done by the airplane during the climb, which is equal to its change in gravitational potential energy:
where
mg = 11,000 N is the weight of the airplane
is the change in height
Substituting,
Now we can calculate the power delivered, which is given by
where
is the work done
is the time taken
Substituting,
Finally, we can convert the power into horsepower (hp), keeping in mind that
Therefore,
Learn more about power:
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