# Change in momentum in a photon collision?

Let's say I drop a ball on the ground and it bounces up. According to classical physics, once the ball hits the ground it goes trough a short phase of deceleration until the velocity reaches zero, then it goes trough a quick phase of acceleration upwards. A shorter deceleration time implies a greater normal force acting on the ball.

From my understanding, a photon must be traveling at the speed of light at all times. This means that if it bounces off something, there is no deceleration phase, but rather it instantly changes it's momentum in another direction. If we think about the example above with the ball, in some sense the electron should experience an infinite normal force, but clearly this does not happen. Of course a hue difference is that the ball has mass while the photon does not, but the photon still has momentum. What is really going on to prevent this?

P.S. I am a layman, I understand mathematical equations and basic physics, but please try to avoid using highly specialized terminology.