The frequency of bird chirping hear by hiran will be 1.77 kHz.
<u>Explanation:</u>
As per Doppler effect, the observer will feel a decrease in the frequency of the receiving signal if the source is moving away from the observer. So the shifted frequency is obtained using the below equation:

Here , c is the speed of sound, Vs is the velocity of source with which it is moving away. f is the original frequency of source and f' is the frequency shift heard by the observer.
As here, f = 1800 Hz, Vs= 6 m/s and c = 343 m/s, then

So, the frequency of bird chirping hear by hiran will be 1.77 kHz.
Answer:
Explanation:
Given that on the tree the gravitational energy stored is 8J
Then, mgh = 8J.
The apple begins to fall and hit the ground, what is the maximum kinetic energy?
Using conservation of energy, as the above is about to hit the ground, the apple is at is maximum speed, and the height then is 0m, so the potential energy at the ground is zero, so all the potential of the apple at the too of the tree is converted to kinetic energy as it is about to hits the ground. Along the way to the ground, both the Kinetic energy and potential energy is conserved, it is notice that at the top of the tree, the apple has only potential energy since velocity is zero at top, and at the bottom of the tree the apple has only kinetic energy since potential energy is zero(height=0)
So,
K.E(max) = 8J
I would go with b because the seasons are caused by the tilt of Earth axis, not greenhouse gases
The efficiency of steam engine is 26.66 %.
<h3>What is Efficiency?</h3>
The efficiency is defined as the work done by the engine divided by the heat supplied.
Work done is the difference between the heat supplied and heat rejected.
So, efficiency η = (Qs -Qr) / Qs
Given is the heat supplied Qs = 225 Joules and heat rejected Qr =285 . then the work done is
W = 225 -225 = - 60 Joules
Efficiency η = 60/225 x 100%
η = 26.66 %
Thus, the efficiency of the steam engine is 26.66 %.
Learn more about efficiency.
brainly.com/question/13828557
#SPJ2
conducted
Conduction occurs when a substance is heated, particles will gain more energy, and vibrate more. These molecules then bump into nearby particles and transfer some of their energy to them. This then continues and passes the energy from the hot end down to the colder end of the substance.