A. 320 g
B. 160 g
C. 80 g
D. 40 g
Pitch is directly related to the frequency of the sound. In this item, we are given that the frequency of the sound is higher compared to those which are audible to the human being's ears. The pitch therefore of the dog's whistle is high.
On the other hand, the frequency and the wavelength of a certain wave are inversely proportional. This means that the high frequency wave will have a short wavelength.
Hence, the answer to this item would have to be "high pitch with a short wavelength"
The answer to this item is the second option.
Answer: plane speed is 94.87m/s
Explanation: since the plane move upward in a semicircular path, the acceleration is a centripetal acceleration with radius of 500metre. But the Centripetal acceleration is given as
Centripetal acceleration
= Speed ²/radius
Making speed subject of formula we have,
Speed² = centripetal acceleration*radius
Speed² = 18*500
=9000
Speed =√9000
= 94.87m/s
Answer:
a
b
Explanation:
From the question we are told that
The wavelength is 
The energy is 
This energy is mathematically represented as
Where c is the speed of light with a value 
h is the Planck's constant with the value 
n is the number of pulses
So
substituting values
Given that the pulses where emitted 20 times in one second then the period of the pulse is
Hence the average power of photons in one 80-mJ pulse during 1 s is mathematically represented as
substituting values
From our studies of the work of Professor Newton,
we have learned that
F = M a .
That is, the product of an object's mass and its acceleration
is equal to the net force acting on it.
An object in equilibrium is an object that has no acceleration.
In other words, it may be moving in a straight line at a speed
that does not change, or it may be just lying there before us.
In either case, since the object has no acceleration, we glance
at Newton's formula, and we instantly realize that the net force
on the object must be ZERO.
The object behaves just as if there were NO forces acting on it at all.
