Answer:
Answer: Kelvin ________________
The electrostatic force between two charges is given by

where
ke is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the charges
In our problem,



Therefore the electrostatic force is
Power is defined as rate of work done which means it is work done in 1 second of time
Now it is given that we have a horse that will give power 745.7 W
So it will do work of 745.7 J in 1 second of time
now if we wish to find the work done by horse in 0.55 s
so we can say



So it will do total work of 410.14 J in 0.55 s of time
Answer : The energy released in first step of thorium-232 decay chain is 
Explanation :
First we have to calculate the mass defect
.
The balanced reaction is,

Mass defect = Sum of mass of product - sum of mass of reactants


conversion used : 
Now we have to calculate the energy released.



The energy released is 
Therefore, the energy released in first step of thorium-232 decay chain is 
Answer:
The magnitude of the magnetic field vector is 1.91T and is directed towards the east.
The steps to the solution can be found in the attachment below.
Explanation:
For the charge to remain in the the earth' gravitational field the magnetic force on the charge must be equal to the earth's gravitational force on the charge and must act opposite the direction of the earth's gravitational force.
Fm = Fg
qvBSin(theta) = mg
Where q = magnitude of charge
v = magnitude of the velocity vector = 4 x10^4 m/s
B = magnitude of the magnetic field vector
theta = the angle between the magnetic field and velocity vectors = 90°
m = mass of the charge = 0.195g
g = acceleration due to gravity =9.8m/s²
On substituting the respective values of all variables in the equation (1) above
B = 1.91T
The direction of the magnetic field vector was found by the application of the right hand rule: if the thumb is pointed in the direction of the magnetic force and the index finger is pointed in the direction of the velocity vector, the middle finger points in the direction of the magnetic field.
Below is the step by step procedure to the solution.