Explanation :
When an electron jumps from one energy level to another, the energy of atom gets changed.
If a photon gets absorbed, the electron will move to higher energy levels and then fall back to the lower energy levels. Then each time a photon will be absorbed whose energy is given by difference between the initial and final energy levels i.e
In Balmer series, the transition is from higher energy levels to n = 2.
So, the necessary condition for Balmer series is that the electron should be at first excited state or n = 2 level as shown in figure.
Answer:
Answer is C
Explanation:
Let's say the pendulum starts swinging from its max height from the left. It then will go down and reach the equilibrium position, this will make it lose GPE while gaining KE (the loss in GPE = gain in KE). At the equilibrium position it has the max KE (max velocity) and minimum GPE. After passing the equilibrium it then starts to head up to the max height on the right, the pendulum gains GPE while losing KE and at the top will have minimum KE while having max GPE. Meaning throughout its joruney the total energy remains constant as
Total energy = KE + GPE
I have attached a simple diagram below, the y axis is the energy and x axis being the time (where t = 0 is the pendulum starting from max height left of the equilibrium). The green curve the the GPE and blue curve is KE. Red line shows that at all times the energy is constant.
Kinetic Energy = 1/2xmassx(velocity)^2
Input values;
K.E=1/2x7kgx(4m/s)^2
K.E.=56J
Answer:
a. 
b. 
c. 
Explanation:
Use Gravitational Force:
Use values given to have the results.
b.
Use m as the mass of the Moon. Using values of a. and m you have the answer.
c.
Use M mass of the planet. Use value of a and Mass of Planet.
Answer:
141.42 km/h
Explanation:
Since this is a 100km/h right angle crosswind, the speed vector with respect to the ground is the vector speed of the airplane with respect to air + the vector speed of the cross-wind with respect to the ground
<100,0> + <0,100> = <100,100>
This vector has a magnitude of
km/h
