Answer:
A skater glides along a circular path. She defines a certain point on the circle as her origin. Later on, she passes through a point at which the distance she has traveled along the path from the origin is smaller than the magnitude of her displacement vector from the origin.
So here in circular motion of the skater we can see that the total path length of the skater is along the arc of the circle while we can say that displacement is defined as the shortest distance between initial and final position of the object.
So it is not possible in any circle that arc-length is less than the chord joining the two points on the circle
As we know that arc length is given as

length of chord is given as

so here


so we have

A.The swimmer pushes the water
C. the walls force against the ball
Answer:
if he is chasing his tail faster with each circle, then that would be acceleration, If not then no
I think it’s R=U/I = 120/5 = 24
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