A2 = 16 m^2
Explanation:
Application of Pascal's law:
F1/A1 = F2/A2
Given:
F1 = 50 N. A1 = 1 m^2
F2 = 800 N A2 = ?
A2 = (F2/F1)A1 = (800 N/50 N)(1 m^2)
= 16 m^2
Answer:
1. Reflection
2. travel from one medium to another
3. Same waves to travel in opposite direction.
Explanation:
1. When a wave strikes a solid barrier, it bounces back in the same medium. This wave behavior of bouncing back is known as reflection. Its like a basketball hitting a backboard. The ball bounces back at the same angle as it was incident. ∠i = ∠r
2. For refraction to occur in a wave, the wave must travel from one medium to another. When light travels from through mediums of different optical densities, it bends. The wave bends away normal when it enters from denser medium to rarer medium. The wave bends towards the normal when it enters from rarer to denser medium. The angle of refraction and angle of incidence are related by Snell's law.

3. The formation of standing wave requires two same waves to travel in the opposite direction and interfere. The incident wave and reflected wave when interfere, form standing waves. There waves are also resonances or harmonics. A standing wave oscillates at one place and does not transfers any energy.
When we first dig into soil, it's nice and soft.( Depending on what soil it is; usually topsoil)
But when we go deeper into it, there are rocks and the soil is harder. There is bedrock at the bottom, subsoil in the middle, and topsoil at the top, which is where we walk.
High task repitition, forceful exertions, repetitive or sustained awkward posture