A glider of mass 0.240 kgkg is on a horizontal track, attached to a horizontal spring of force constant 6.00 N/mN/m. There is friction between the track and the glider. Initially the spring (whose other end is fixed) is stretched by 0.100 mm and the attached glider is moving at 0.400 m/sm/s in the direction that causes the spring to stretch farther. The glider comes momentarily to rest when the spring is stretched by 0.112 mm. How much work does the force of friction do on the glider as the stretch of the spring increases from 0.100 mm to 0.112 mm?

1.   what is light?

light is an electromagnetic wave visible to the human eye. 

2. what is a reflection?

the rebounding of a light ray when it hits a mirror.

3. what is the incident ray?

contacts the surface of an object.

4. what is the reflected ray?

bounces off a reflective surface.

5. what is the normal ray?

perpendicular to the surface of a mirror.

6. what is the angle of incidence?

an angle formed by the incident ray and the normal.

7. what is the angle of reflection?

an angle formed by the reflected ray and the normal.

8. what is refraction?

(bending.)

9. what is a converging lens?

bring together light rays that pass through.

10. what is a diverging lens?

spreads out light passing through.

11. focal point?

the real point where the refracted rays meet when the incident rays run parallel.

i copy pasted btw from an website..