A convex refracting surface has a radius of 12 cm. Light is incident in air (n = 1) and refracted into a medium with an index of refraction of 2. Light incident parallel to the central axis is focused at a point: Group of answer choices 3 cm from the surface 6 cm from the surface 24 cm from the surface 12 cm from the surface 18 cm from the surface

A60-kg box is being pushed a distance of 6.8 m across the floor by a force p with arrow whose magnitude is 162 n. the force p with arrow is parallel to the displacement of the box. the coefficient of kinetic friction is 0.24. determine the work done on the box by each of the four forces that act on the box. be sure to include the proper plus or minus sign for the work done by each force. (the floor is level and horizontal. forces that act on the box: pushing force p, frictional force f, normal force n, and weight mg.)