Answer:
The orbital speed of the electron is 2.296 x 10⁶ m/s
Explanation:
Given;
radius of the circular orbit, r = 5.041 × 10⁻¹¹ m
In the Bohr’s model of the hydrogen atom, the velocity of the electron is given as;

where;
h is Planck's constant
m is mass of electron
r is the radius of the circular orbit
n is the energy level of hydrogen in ground state
Substitute in these values and solve for V

Therefore, the orbital speed of the electron is 2.296 x 10⁶ m/s
Answer:
c) 100,000 m/s
Explanation:
You need to take the same wave length from the top graph and bottom one, so let's take half a wave length then in the top one that is 0.005, but in the bottom one it's 2000/4 = 500 because they are smaller and there are 4 half waves before you get to 2000, whereas in the top one there is 1 half wave before you get to 0.005 on the graph.
Now use speed = distance / time
speed = 500 / 0.005 = 100 000 m/s
Answer:
(D) friction from the ground changes the ball's
kinetic energy into heat
Explanation:
When a ball is roll on the ground, the electrons in the atoms on the surface of the ground push against the electrons in the atoms on the surface of your ball that is touching the ground. A rolling ball stops because the surface on which it rolls resists its motion,that is when two surfaces come in contact with each other, the surface of one tends to oppose the motion of the other. A rolling ball stops because of friction.
Answer:
a) T = 0.5 s
b) v = 1.2π m/s ≈ 3.77 m/s
Explanation:
It makes two revolutions in one second so makes one revolution in ½ second
circumference of the circle is
C = 2πr = 0.6π m
which it traverses in one time period
0.6π m / 0.5 s = 1.2π m/s