Where would the image be located for an object placed 20 cm, along the principal axis, from a double convex lens with a focal length of 10 cm? Is the image upright or inverted?

Hence the image will be formed on the left side of the lens (shown by negative sign) at a distance of 20 cm. Also we can see that the object is in between the lens and image, hence the image is virtual.

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.