Aconvex lens has a focal length of 16.5 cm. where on the lens axis should an object be placed in order to get a virtual, enlarged image with a magnification of 1.90?

Object should be placed at a distance, u = 7.8 cm

Given:

focal length of convex lens, F = 16.5 cm

magnification, m = 1.90

Solution:

Magnification of lens, m = -

where

u = object distance

v = image distance

Now,

1.90 =

v = - 1.90u

To calculate the object distance, u by lens maker formula given by:

u = 7.8 cm

Object should be placed at a distance of 7.8 cm on the axis of the lens to get virtual and enlarged image.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.