I think it’s a nebula i hope it’s right
Answer:
Work, W = 846.72 Joules
Explanation:
Given that,
Mass of the watermelon, m = 4.8 kg
It is dropped from rest from the roof of 18 m building. We need to find the work done by the gravity on the watermelon from the roof to the ground. It is same as gravitational potential energy i.e.
W = mgh
W = 846.72 Joules
So, the work done by the gravity on the watermelon is 846.72 Joules. Hence, this is the required solution.
Answer:
a) The velocity of the car is 7.02 m/s and the car is approaching to the police car as the frequency of the police car is increasing.
b) The frequency is 1404.08 Hz
Explanation:
If the police car is a stationary source, the frequency is:
(eq. 1)
fs = frequency of police car = 1200 Hz
fa = frequency of moving car as listener
v = speed of sound of air
vc = speed of moving car
If the police car is a stationary observer, the frequency is:
(eq. 2)
Now,
fL = frequecy police car receives
fs = frequency police car as observer
a) The velocity of car is from eq. 2:

b) Substitute eq. 1 in eq. 2:

Astronomers thought that a nova was a new star, appearing for the first time in the heavens, today we know that it is as a binary star system.
<h3>What is the binary star system about?</h3>
A binary star system is known to be one where one star is known to be called a white dwarf and there is a mass that is said to be transferred to it
A binary star is known to be a kind of a system that is composed of two stars that are known to be gravitationally held together to and in orbit near each other.
Note that Binary stars in the night sky are ones that are often seen as a single object and thus Astronomers thought that a nova was a new star, appearing for the first time in the heavens, today we know that it is as a binary star system.
Learn more about astronomers from
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