Answer:
When walking towards the back of a bus while it moves forward its apparent velocity seems slower than it actually is with respect to the ground.
Explanation:
- When a someone follows a moving bus from behind by walking then the apparent speed of the bus is slightly slower by the same magnitude as the speed of walking because both are moving in the same direction.
- This is the concept of relative velocity when the apparent velocity of the same object appears different to different viewers at the same time being on different frame of motion.
- When the same bus is observed from a point on the road the speed of the bus will appear greater than the former case discussed above because the bus here is moving with respect to a stationary observer.
Answer: The speed of wave is 2m/s.
Explanation:
The speed of wave equals to the distance/time. So when we divide 4m and 2s, we get that the speed of wave is 2m/s
Answer:
The energy of the photon is 
Explanation:
From the question we are told that
The first orbit is 
The second orbit is 
According to Bohr model
The energy of difference of the electron as it moves from on orbital to another is mathematically represented as
![\Delta E = k [\frac{1}{n^2 _1} + \frac{1}{n^2 _2} ]](https://tex.z-dn.net/?f=%5CDelta%20%20E%20%3D%20k%20%5B%5Cfrac%7B1%7D%7Bn%5E2%20_1%7D%20%20%2B%20%5Cfrac%7B1%7D%7Bn%5E2%20_2%7D%20%5D)
Where k is a constant which has a value of 
So
![\Delta E = - 2.179 * 10^{-18} [\frac{1}{5^2 _1} + \frac{1}{2^2 _2} ]](https://tex.z-dn.net/?f=%5CDelta%20%20E%20%3D%20-%202.179%20%2A%2010%5E%7B-18%7D%20%5B%5Cfrac%7B1%7D%7B5%5E2%20_1%7D%20%20%2B%20%5Cfrac%7B1%7D%7B2%5E2%20_2%7D%20%5D)

Now we are told from the question that

so x eV =
Therefore


Answer:
right one is more efficient
Explanation:
Answer:
It takes
for the radio signal to travel from earth to the spaceship.
Explanation:
Given:
The frequency of the radio signal =
hertz
Distance =
meters
To Find:
The time taken for the radio signal to travel from the earth to the spaceship= ?
Solution:
we know that the time taken can be found by dividing the distance travelled by the speed at which the signal travels
So

Here the speed of the radio signal is equal the the speed of light
Now substituting the values,
Time taken is
=>
=>
=>