An object rotates describing a horizontal circumference when subjected to a centripetal force F. What centripetal force will act on the object if the radius of the circle is doubled and the kinetic energy of the object is halved? A) F/4 B) F/2 C) F D) 4F please explain this to me : (

Option A:  F/4

Explanation:

Centripetal force,

Where v = speed

r = radius

Since Kinetic Energy,

Writing centripetal force in terms of kinetic energy,

If the initial radius of the circle, r₁ =r

The doubled radius, r₂ = 2r

If the initial kinetic energy,

The halved kinetic energy,  

Therefore, the new Centripetal force becomes:

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

which statement about this sum is true? −245+2.7