An element with 83 protons has the atomic number 83. If you look at a periodic table you will see Bismuth is the element with the atomic number of 83. It will have a positive charge of +3 because it has only 80 electrons and 83protons. 83-80=+3.
Answer:
The magnitude of the external electric field at P will reduce to 2.26 x 10⁶ N/C, but the direction is still to the right.
Explanation:
From coulomb's law, F = Eq
Thus,
F = E₁q₁
F = E₂q₂
Then
E₂q₂ = E₁q₁

where;
E₂ is the external electric field due to second test charge = ?
E₁ is the external electric field due to first test charge = 4 x 10⁶ N/C
q₁ is the first test charge = 13 mC
q₂ is the second test charge = 23 mC
Substitute in these values in the equation above and calculate E₂.

The magnitude of the external electric field at P will reduce to 2.26 x 10⁶ N/C when 13 mC test charge is replaced with another test charge of 23 mC.
However, the direction of the external field is still to the right.
Answer:
Explanation:
ASSUMING your speed is constant
f₀ = f(v + vo)/(v + vs)
Δf = f approach - f depart
69.5 = (769(343 + vo)/(343 + 0)) - (769(343 - vo)/(343 + 0))
69.5 = 769(2vo/343)
vo = 15.5 m/s
Answer:
She must be launched with minimum speed of <u>57.67 m/s</u> to clear the 520 m gap.
Step-by-step explanation:
Given:
The angle of projection of the projectile is,
°
Range of the projectile is,
m.
Acceleration due to gravity, 
The minimum speed to cross the gap is the initial speed of the projectile and can be determined using the formula for range of projectile.
The range of projectile is given as:

Plug in all the given values and solve for minimum speed,
.

Therefore, she must be launched with minimum speed of 57.67 m/s to clear the 520 m gap.
Answer:
16. c
17. d
Explanation:
16. Newton’s third law states that a force will always have an opposite but equal force as a reaction, so every force comes as a pair of action-reaction forces. For example, if you push on a book, the book also pushes on you.
17. If 1cm represents 15N, then 5cm must represent 15N*5=75N.