How many times is a ray of light reflected by 2 plane mirrors placed parallel and facing each other

the ray is reflected infinite number of times by 2 plane mirrors placed parallel to each other as each reflected ray would be the incident ray for the other.

Explanation:

the ray is reflected infinite number of times by 2 plane mirrors placed parallel to each other as each reflected ray would be the incident ray for the other.

Placing one mirror at an angle causes reflections to curve.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards