Answer:
The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency is 15.7 m/s
Explanation:
The Doppler shift equation is given as follows;
Where:
f' = Required observed frequency = 20.0 kHz
f = Real frequency = 21.0 kHz
v = Sound wave velocity = 330 m/s
= Observer velocity = X m/s
= Source velocity = 0 m/s (Assuming the source is stationary)
Which gives;
330 - = (20/21)*330
= 330 - (20/21)*330 = 15.7 m/s
The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency = 15.7 m/s.
Answer:
Explanation:
Given
for 
Sphere are 
when sphere 
apart suppose deflection is 
We know
Where F=force between charged particle
Deflection
thus 
for
(b)for 
deflection Potential 
Electric Potential is 
where V=voltage
k=constant
r=distance between charges
Put value of Q in equation 1
thus 
therefore
Answer:
Explanation:
As per the first law of thermodynamics,
U is change in the internal energy of the system and W is work done on the system.
Answer:
Assume that 
. The net force on this object will be 
(downwards.) The acceleration of this object will be approximately 
(also downwards.)
Explanation:
<h3>Net force</h3>
The object is falling towards the ground because of gravity. The size of the gravitational force on this object depends on its mass and the strength of the gravitational field at its location.
Near the surface of the earth, the gravitational field strength is approximately 
. In other words, approximately 
of gravitational force acts on each kilogram of mass near the surface of the earth.
The mass of this object is given as 
. Therefore, the size of the gravitational force on it will be:
.
Near the surface of the earth, gravitational forces point towards the ground. On the other hand, the direction of air resistance on this object will be opposite to its direction of motion. Since this objects is moving towards the ground, the air resistance on it will be directed in the opposite direction. That's exactly the opposite of the direction of the gravitational force on this object. The net force on this object will be:
.
<h3>Acceleration</h3>
Let 
denote the acceleration on this object. Apply Newton's Second Law of motion:
.
Note that the acceleration of this object and the net force on it should be in the same direction.
