Answer:
The energy in its ground state is 10 meV.
Explanation:
It is given that,
The energy of the electron in its first excited state is 40 meV.
Energy of the electron in any state is given by :

For ground state, n = 1
.............(1)
For first excited state, n = 2
.............(2)
Dividing equation (1) and (2), we get :


So, the energy in its ground state is 10 meV. Hence, this is the required solution.
when the apple moves in a horizontal circle, the tension force in the string provides the necessary centripetal force to move in circle. the tension in the string is given as
T=mv²/r
where T = tension force in the string , m = mass of the apple
v = speed of apple , r = radius of circle.
clearly , tension force depends on the square of the speed. hence greater the speed, greater will be the tension force.
at some point , the speed becomes large enough that it makes the tension force in the string becomes greater than the tensile strength of the string. at that point , the string breaks
The average velocity of the car for the whole journey is 69.57 km/h.
The given parameters:
- <em>Length of the road, L = 320 km</em>
- <em>Distance covered = 240 km at 75 km/h</em>
- <em>time spent refueling, t₂ = 0.6 hr</em>
- <em>Final velocity, = 100 km/hr</em>
The time spent by the before refueling is calculated as follows;

The time spent by the car for the remaining journey;

The total time of the journey is calculated as follows;

The average velocity of the car for the whole journey is calculated as follows;

Learn more about average velocity here: brainly.com/question/6504879
H2O2 H2O
H2 + O2 → H2O. Word equation: Hydrogen gas + Oxygen gas → water. Type of Chemical Reaction: For this reaction we have a Combination reaction. Balancing Strategies: For this reaction it is helpful to start by changing the coefficient in front of H2O and so that you have an even number of oxygen atoms.