Answer:
a) 
b) 
c) 
d) 
Explanation:
a) We can find the electron's speed by knowing the kinetic energy:

Where:
K: is the kinetic energy = 1.59 keV
m: is the electron's mass = 9.11x10⁻³¹ kg
v: is the speed =?

b) The electron's speed can be found by using Lorentz's equation:
(1)
Where:
F: is the magnetic force
q: is the electron's charge = 1.6x10⁻¹⁹ C
θ: is the angle between the speed of the electron and the magnetic field = 90°
The magnetic force is also equal to:
(2)
By equating equation (2) with (1) and by solving for B, we have:

c) The circling frequency is:

Where:
T: is the period = 2π/ω
ω: is the angular speed = v/r

d) The period of the motion is:

I hope it helps you!
T² caries directly as R³ .
This is Kepler's 3rd law of planetary motion .
Potential energy, is energy due to its position.
Given: Mass m = 40 Kg; Height h = 50 m
Required: Potential energy P.E = ?
Formula: P.E = mgh P.E = (40 Kg)(9.8 m/s²)(50 m)
P.E = 19,600 J
Answer:
Explanation:
Let m be the mass of Astronaut
M=mass of earth
G=Gravitational constant
R=radius of Earth
Force Exerted by Earth on Astronaut

acceleration due to gravity is 

When it is at

The force that causes a satellite to orbit Earth is gravity ------ True