The angle of incidence and the angle of reflection are measured from the the perpendicular to the surface.

a. planar
b. normal

What are atoms of the same element with varying number of neutrons

14. a body is projected with velocity vi from a. at the same time another body is projectedvertically upwards from point b withvelocity v2 lies vertically below the highestpoint. both the bodies collide thenv2÷v1is

Coal contains energy. a. light b. kinetic c. chemical d. mechanical