Answer:
The correct option is (B).
Explanation:
The Kepler's third law of motion gives the relationship between the orbital time period and the distance from the semi major axis such that,
It is mentioned that, an asteroid with an orbital period of 8 years. So,
So, an asteroid with an orbital period of 8 years lies at an average distance from the Sun equal to 4 astronomical units.
Answer:
f=8.219*10^{8}Hz
Explanation:
We are going to use the formula v=fλ
Where v= velocity of radio waves
f= frequency
λ= wavelength of wave
- radio waves are electromagnetic waves and as such they have the speed of light which is 3*10^{8}m/s.
- also when a wave travels from one medium to another, the wavelength changes while the frequency remains the same.
- calculating for the frequency of the wave in air also gives us the frequency in the window glass.
f=\frac{v}{λ}
v=3*10^{8}m/s.
λ=36.5 cm = 36.5/100= 0.365m
f=\frac{3*10^{8}m/s.}{0.365m}
f=8.219*10^{8}Hz
Hertz is a measurement of the frequency that a wave is occurring.
Answer:
The torque on the child is now the same, τ.
Explanation:
- It can be showed that the external torque applied by a net force on a rigid body, is equal to the product of the moment of inertia of the body with respect to the axis of rotation, times the angular acceleration.
- In this case, as the movement of the child doesn't create an external torque, the torque must remain the same.
- The moment of inertia is the sum of the moment of inertia of the merry-go-round (the same that for a solid disk) plus the product of the mass of the child times the square of the distance to the center.
- When the child is standing at the edge of the merry-go-round, the moment of inertia is as follows:
- When the child moves to a position half way between the center and the edge of the merry-go-round, the moment of inertia of the child decreases, as the distance to the center is less than before, as follows:
- Since the angular acceleration increases from α to 2*α, we can write the torque expression as follows:
τ = 3/4*m*r² * (2α) = 3/2*m*r²
same result than in (2), so the torque remains the same.
Answer
Given,
Periscope uses 45-45-90 prisms with total internal reflection adjacent to 45°.
refractive index of water, n_a = 1.33
refractive index of glass, n_g = 1.52
When the light enters the water, water will act as a lens and when we see the object from the periscope the object shown is farther than the usual distance.
