a) the number of protons is 
more than the electrons
b) 
Explanation:
The net electric charge on the ball is
This electric charge is given by the algebraic sum of the charge of the protons and of the charge of the electrons.
The charge of one proton is:
While the charge of one electron is
So the net charge on the metal ball will be given by
where
is the number of protons
is the number of electrons
So we find:
This means that the number of protons is more than the electrons.
b)
In this case, we want to make the ball neautral, so we have to remove a net charge of Q' such that the new charge is zero:
This implies that the charge that we must remove is
To do that (and to make the ball losing mass at the same time), we have to remove protons, since they have positive charge.
The number of protons that must be removed is:
The mass of one proton is
Therefore, the total mass that must be removed from the ball is
Answer:
1027 N/C
3.42 x 10⁻⁶ T
Explanation:
I = Intensity of electromagnetic field = 1400 W/m²
E₀ = Maximum value of electric field
Intensity of electromagnetic field is given as
I = (0.5) ε₀ E₀² c
1400 = (0.5) (8.85 x 10⁻¹²) (3 x 10⁸) E₀²
E₀ = 1027 N/C
B₀ = maximum value of magnetic field
using the equation
E₀ = B₀ c
1027 = B₀ (3 x 10⁸)
B₀ = 3.42 x 10⁻⁶ T
Answer:
B train!
Explanation:
A train travelled at 40 km/hr. (120/3)
B train traveled at 45 km/hr (180/4)
Answer:
29.4m/s
Explanation:
Given parameters:
Time = 3s
Unknown:
Average velocity = ?
Solution:
To solve this problem, we use the expression below:
v = u + gt
v is the average velocity
u is the initial velocity = 0m/s
g is the acceleration due to gravity = 9.8m/s²
t is the time
So;
v = 0 + (9.8 x 3) = 29.4m/s
