A body moves in a circle at constant speed. Does the centripetal force that accelerates the body do any work? Explain.

If a body moves in a circular path then centripetal force that accelerates the body does not do any work

Explanation:

Reason 1:

As we know that work done on a body is equal to the force applied multiplied by the displacement covered i.e. W=Force.displacement

When a body is moving in a circular path it means it is coming back to the starting point so its displacement is zero thus work done by a body moving in a circular path with a constant speed is zero.

i.e. Work-done=force.0

W=0  

Reason 2:

As we know that work done on a body is equal to the force applied multiplied by the displacement covered in the direction of force applied but if the force is inclined at an angle then work done on a body is equal to the product of the component of force in the direction of displacement and its displacement.

W=F.S cosθ

As the force on the body is centripetal force which is always directed towards the center of the circle (i.e. acting along the radius of the circle) which is  at right angle to the direction of the displacement (i.e. the direction of the displacement is always tangential to the circle)

i.e. θ=90°

W=F.S cos90°

W=F.S×0

W=0

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

c) up is the direction the magnetic force is acting on the charge.