Answer:
Explanation:
Given
length of window 
time Frame for which rock can be seen is 
Suppose h is height above which rock is dropped
Time taken to cover 
so using equation of motion
where y=displacement
u=initial velocity
a=acceleration
t=time
time taken to travel h is
Subtract 1 and 2 we get
and from equation 
so 
and 
so 
substitute the value of 
in equation 2
Answer:
Option (b) is correct.
Explanation:
Elastic collision is defined as a collision where the kinetic energy of the system remains same. Both linear momentum and kinetic energy are conserved in case of an elastic collision.
Inelastic collision is defined as a collision where kinetic energy of the system is not conserved whereas the linear momentum is conserved. This loss of kinetic energy may due to the conversion to thermal energy or sound energy or may be due to the deformation of the materials colliding with each other.
As given in the problem, before the collision, total momentum of the system is 
and the kinetic energy is 
. After the collision, the total momentum of the system is , but the kinetic energy is reduced to 
. So some amount of kinetic energy is lost during the collision.
Therefor the situation describes an inelastic collision (and it could NOT be elastic).
Answer:
You are a guest magician in a circus. One of your tricks is to place a football on an inclined plane without the football rolling over is explained below in details.
Explanation:
spinning ball halts after traveling some range due to friction energy act different direction of movement of the ball. you can observe in the figure.
Let any rolling ball of mass (m ) is traveling with velocity v ,
common effect on ball (N) = mg
because of motion, friction energy develops on the contact exterior and begins to resist the movement of the rolling ball.
hence,
fr = uN = umg act on communicating exterior, so, after any time due to friction energy rolling ball gets to rest.
125 cm^3 ——————)-)-()-)))-
Answer:
Minimum distance needed to move one of the mirrors = 125 nm
Explanation:
Constructive interference occurs when the maxima (trough or crest) of two waves that are in phase add together so that the amplitude of the resulting wave is equal to the sum of the individual amplitudes.
Destructive interference occurs when the maxima (trough or crest) of two waves that are out of phase by 180⁰ or half a wavelength combine to produce a smaller amplitude than the individual amplitudes that combine. It can even produce a wave of zero amplitude.
Since the spot of constructive interference has been changed to destructive interference, Path difference = Wavelength/2
Path difference = 500nm/2 = 250 nm
Path difference = 250 * 10⁻⁹ m
Since there are two interferometer's mirrors and only one is moved, the minimum distance will be a half of the path difference.
That is, minimum distance = (path difference)/2
Minimum distance = (250 * 10⁻⁹)/2
Minimum distance = 125 * 10⁻⁹ m
Minimum distance = 125 nm
