Answer:
c. The forces acting on the box are balanced.
Answer:

Explanation:
Let hockey puck is moving at constant speed v
so here we have

so time taken by the puck to strike the wall is given as

now time taken by sound to come back at the position of shooter is given as


so we know that total time is 1.9 s




now we have


The angle of incidence for a ray of light passing through the center of curvature of a concave mirror is 0°.
The angle of incidence is the angle between the surface's normal and the incident ray. For a concave mirror, the normal of the surface is along the center of the curvature, and a ray of light passed through a center of curvature passes through the normal of the surface.
The ray of light retreats its path making a zero angle of reflection. The law of reflection state that the angle of incidence is equal to the angle of reflection; therefore, the angle of incidence of a concave surface passed through the center of curvature is zero degrees.
Learn more about the angle of incidence here:
brainly.com/question/3432273
#SPJ4
I would say by putting two fingers under your chin or putting two fingers on the back of your wrist, hope i helped ! :)