Answer:
D and A
Explanation:
Hint The basic difference between them is that a bar magnet is a permanent magnet whereas an electromagnet is a temporary magnet. An electromagnet is formed when an electric current is passed through wires wound around soft metalcore. An electromagnet loses its magnetism once the current flow is stopped.
Answer:
The time elapses until the boat is first at the trough of a wave is 4.46 seconds.
Explanation:
Speed of the wave, v = 59 km/h = 16.38 m/s
Wavelength of the wave, 
If f is the frequency of the wave. The frequency of a wave is given by :

The time period of the wave is given by :

We need to find the time elapses until the boat is first at the trough of a wave. So, the time will be half of the time period of the wave.

Hence, this is the required solution.
Answer:
Magnitude of resultant = 131.15
Direction of resultant = 3.97°
Explanation:
||u|| = 70
θ = 40°


||v|| = 85
θ = 335°


Resultant


Magnitude of resultant = 131.15
Direction of resultant = 3.97°
Answer:
It can be concluded that the star is moving away from the observer.
Explanation:
Spectral lines will be shifted to the blue part of the spectrum if the source of the observed light is moving toward the observer, or to the red part of the spectrum when is moving away from the observer (that is known as the Doppler effect).
The wavelength at rest for this case is 434 nm and 410 nm (
,
)

Since,
(444nm) is greater than
(434 nm) and
(420nm) is greater than
(410 nm), it can be concluded that the star is moving away from the observer
Answer:
Explanation:
Given
Horizontal bar rises with 300 mm/s
Let us take the horizontal component of P be


where
is angle made by horizontal bar with x axis
Velocity at y=150 mm

thus 
position of


Velocity at this instant

