Answer: 500 s
Explanation:
Speed 
is defined as a relation between the distance 
and time 
:
Where:
is the speed of light in vacuum
is the distance between the Earth and Sun
is the time it takes to the light to travel the distance
Isolating :
Finally:
Answer:
Explanation:
When we apply a horizontal force of 76 N to a block, the block moves across the floor at a constant speed. So net force on the block is zero .
It implies that a force ( frictional ) acts on it which is equal to 76 N in opposite direction ( friction )
When we apply a greater force on it it starts moving with acceleration .
This time kinetic friction acts on it due to rough ground equal to 76 N .This is limiting friction ( maximum friction )
Net force on the body in later case
= 89 - 76
= 13 N
Force by ground on the block in horizontal direction = 76 N ( FRICTIONAL FORCE )
=
The correct answer is: Option (D) length, speed
Explanation:
According to Faraday's Law of Induction:
ξ = Blv
Where,
ξ = Emf Induced
B = Magnetic Induction
l = Length of the conductor
v = Speed of the conductor.
As you can see that ξ (Emf/voltage induction) is directly proportional to the length and the speed of the conductor. Therefore, the correct answer will be Option (D) Length, Speed
Answer:
A. False, frequency can increase or decrease wavelength.
For example: a high frequency would mean there are shorter wavelengths that occur in a period. Meanwhile, a low frequency would indicate that the wavelengths are longer and in longer periods.
Answer:
70.07 Hz
Explanation:
Since the sound is moving away from the observer then
and 
when moving towards observer
With 
of 76 then taking speed in air as 343 m/s we have
Similarly, with of 65 we have
Now
v_s=27.76 m/s
Substituting the above into any of the first two equations then we obtain
