Answer:
q₁ = -6.54 10⁻⁵ C
Explanation:
Force is a vector quantity, but since all charges are on the x-axis, we can work in one dimension, let's apply Newton's second law
F = F₁₂ + F₂₃
the electric force is given by Coulomb's law
F = k q₁q₂ / r₁₂²
let's write the expression for each force
F₂₃ = k q₂ q₃ / r₂₃²
F₂₃ = 9 10⁹ 34.4 10⁻⁶ 72.8 10⁻⁶ / 0.1²
F₂₃ = 2.25 10³ N
F₁₂ = k q₁q₂ / r₁₂²
F₁₂ = 9 10⁹ q₁ 34.4 10⁻⁶ / 0.1²
F₁₂ = q₁ 3,096 10⁷ N
we substitute in the first equation
225 = q₁ 3,096 10⁷ +2.25 10³
q₁ = (225 - 2.25 10³) / 3,096 10⁷
q₁ = -6.54 10⁻⁵ C
Answer:
Explanation:
Let the ball is thrown upwards with speed u and reaches upto height h.
Use III equation of motion

here, final velocity v = 0
So, 
Now as the ball reaches the maximum height, it starts falling freely. Let it strkes with the ground with velocity v'.

here, u = 0
So, 
It means the velocity is same as the velocity of projection.