Using Newton's second law;
F = ma, where m = mass, a = acceleration or deceleration
a = Δv/t = (v-u)/t, but v= 0, u = 10 m/s, t = 1.
Then,
a = (0-10)1 = -10 m/s^2
Substituting;
F = ma = 10*-10 = -100 N
The mattress exerts 100 N to stop the ball.
Evidence for the particle nature of light are not: 1. refraction, 2. many colors of light, 3. diffraction. These are all phenomenon that support wave theory of light. Evidence for particle nature of light is photoelectric effect. Because it was discovered that you need discrete energies of light to eject electrons from a metal surface and not continuous as the wave theory of light suggests.
