Answer:
Ruko zara kuch Time dedo na please
False. False.
A lunar eclipse occurs only when the moon is full.
A solar eclipse occurs only when the moon is new.
Answer:
(a) 
(b) The charge inside the shell is placed at the center of the sphere and negatively charged.
Explanation:
Gauss’ Law can be used to determine the system.
This is the net charge inside the sphere which causes the Electric field at the surface of the shell. Since the E-field is constant over the shell, then this charge is at the center and negatively charged because the E-field is radially inward.
The negative charge at the center attracts the same amount of positive charge at the surface of the shell.
Answer:
- A book lying on a table - Balanced force
- An airplane cruising in level flight - Balanced
- A rock falling from a cliff - Unbalanced force
- A bridge collapsing in an earthquake - Unbalanced force
- A man sitting on a park bench - Balanced force
- A space shuttle taking off - Unbalanced force
- A car maintaining a constant speed on a straight road - Balanced force
- An airplane landing - Unbalanced force
Explanation:
Usually, one or more forces act on a body at an instant of time. When these forces acting on a body and bring the body in the equilibrium position, the force is said to be balanced. The unbalanced force changes the equilibrium state of the body.
As in the case of an airplane cruising in a level flight, the weight of the plane will be equal to the lift force and the thrust is equal to the drag. So the plane is experiencing a balanced force.
Answer: If a star's radial velocity is -50 km/s, the frequency of its light would appear to be higher than its true frequency. We usually say that the star's wavelength is blue shifted.
Explanation:
Radial velocity is defined as the velocity of how an object is seen by the axis of a circle.
Then, if the radial velocity is -50km/s, this means that the radius is decreasing, and then that the star is coming towards the viewer.
as the star is coming towards the viewer, we will see a shorter wavelength, which implies that the frequency would appear to be bigger as it really is.
and this is called a blue shift, because the blue light is the visible light with the biggest frequency, while the red light is the visible light with the smallest frequency, then we have:
If a star's radial velocity is -50 km/s, the frequency of its light would appear to be higher than its true frequency. We usually say that the star's wavelength is blue shifted.
