I think its between b or c
Answer:
140°
Explanation:
The law of reflection states that the angle of redlection equals to the angle of incidence.
When light rays hit surface at 20°, they also leave the surface at the same angle
Since the whole surface has 180° then subtracting these two angles from total angle gives the the angle between the incident and reflected rays.
180°-20°-20°=140°
The angle of incidence and reflection are equal hence 140/2=70°
The question needed the angle between the incident and reflected rays which is already calculated as 140°
The work-energy theorem states that the change in kinetic energy of the particle is equal to the work done on the particle:

The work done on the particle is the integral of the force on dx:

So, this corresponds to the change in kinetic energy of the particle.
Answer:
Our planet is surrounded by a layer of gases called the atmosphere. ... ➢ Without our atmosphere, there would be no life on earth. ➢ Scientists divided the atmosphere into four layers according to temperature: troposphere, stratosphere, mesosphere, and thermosphere.
Explanation: