Question

What must be true of a force that causes an object to move in a circular motion?

Answer 1

Before going to answer this question, first we have to understand centripetal force.

The centripetal force is the force which is required to keep the body along its circular path.The direction of the force is along the radius and towards the centre.

$Mathematically\ centripetal\ force\ F_{c} =\frac{mv^2}{r}$

Here m is the mass of the body,v is the velocity of the body and r is the radius of the circular path.

When a body moves in a circular path,its velocity at any point is the tangent drawn at that point.

As centripetal force acts along the radius, it must be perpendicular to the velocity of the body.

Hence the correct answer to the question is- It acts perpendicular to the velocity and is directed toward the center of the circle.

Answer 2

It acts perpendicular to the velocity and it's directed towards the center