Answer:
Velocity is the speed of something given in a direction. the SI unit of velocity is metre per second or m/s.
The acceleration of gravity (on Earth) is 9.8 m/s² downward.
This means that every falling object gains 9.8 m/s more downward speed
every second that it falls.
In 5 seconds of falling, it gains (5 x 9.8 m/s) = 49 m/s of downward speed.
If it was already descending at 2.0 m/s at the beginning of the 5 sec,
then at the end of the 5 sec it would be descending at
(2 m/s + 49 m/s) = 51 m/s .
Answer: A.The total number of energy levels the electron can jump to.
Explanation:
Spectral lines are bright or dark lines over continuous spectrum which occur due to emission or absorption of energy.
When an electron jumps to or from one energy level to another energy level, spectral lines are produced. The range of spectral lines depends on the number of energy levels available to which the electron can jump. This depends the amount of energy gained/lost by the electron.
Thus, the correct answer is: A.The total number of energy levels the electron can jump to.
Answer:
Explanation:
Distance = 50 m
1. To find the average speed, first start the stop watch as the sprinter starts running and then stop it when he reaches the finish line.
Now note the time taken by the sprinter to run for 50 m.
The average speed of the sprinter is defined as the ratio of total distance covered to the total time taken.
Average speed = total distance / total time
2. To find the instantaneous speed, check the seed of the sprinter as he is at the finish line.
Answer:
The angle of diffraction are 67.75 deg and 53.57 deg.
Explanation:
Given:
Davisson and Germer experiment with nickel target for electrons bombarding.
Voltages : 
and 
We have to find the angles that is 
and 
.
Concept:
- Davison Germer experiment is based on de Broglie hypothesis where it says matter has both wave and particle nature.
- When electrons get reflected from the surface of a metal target with an atomic spacing of
, they form diffraction patterns. - The positions of diffraction maxima are given by
. - An atomic spacing is
, when the principal maximum corresponds to n=1 - The wavelength is
, and 
.
Solution:
Finding the wavelength at 
.
⇒ 
⇒ 
nm
Plugging the values of wavelength.
⇒ 
⇒ 
⇒ 
degrees.
Now
For for the electrons with energy , 
the wavelength is.
⇒ 
nm
And
⇒ 
degrees.
So,
The angles of diffraction maxima are 67.75 deg and 53.57 deg.
