The viscous force on an object moving through air is proportional to its velocity.
The only forces acting on an object when falling are air resistance and its weight itself. The weight acts vertically downwards whereas air resistance acts vertically upward.
Let F be the viscous force due to air molecules, B be buoyant force due to air and W be the weight of falling object. Initially, the velocity of falling object and hence the viscous force F is zero and the object is accelerated due to force
(W-B). Because of the acceleration the velocity increases and accordingly the viscous force also increases. At a certain instant, the viscous force becomes equal to W-B. The net force then becomes zero and the object falls with constant velocity. This constant velocity is called terminal velocity.
Thus at terminal velocity, air resistance and force of gravity becomes equal.
Answer: Option (b) is the correct answer.
Explanation:
The given data is as follows.
F = 
N
g = 9.8 m/s
radius = 
= 
= 15 cm = 0.15 m (as 1 m = 100 cm)
Formula to calculate depth is as follows.
F = 
or, h = 
h = 
= 751 m
Thus, we can conclude that the maximum depth in a lake to which the submarine can go without damaging the window is closest 750 m.
#1
As we are increasing the frequency in the simulation the wavelength is decreasing
So if speed remains constant then wavelength and frequency depends inversely on each other
If we are in boat and and moving over very small wavelengths then these small wavelength will be encountered continuously by the boat in short interval of times
#2
As we are changing the amplitude in the simulation there is no change in the speed frequency and wavelength.
So amplitude is independent of all these parameter
Amplitude of wave will decide the energy of wave
So light of greater intensity is the light of larger amplitude
#3
In our daily life we deal with two waves
1 sound waves
2 light waves
