Answer:
1. the force which can be felt or act only when two objects are in contact is known as contact force.
for example: frictional force, muscular force,
tension, air resistance .
2. the force which can be felt or act even when two objects are in contact or not is known as non-contact force.
for example: magnetic force, gravitational force, electrostatic force.
(a) is a decomposition reaction
As the surface given is a smooth surface, we can use specular reflection. According to the law of specular reflection, the angle of incidence equals the angle of reflection, so it will also be 40°. Answer is A.
Answer:
40 m/s
Explanation:
If you multiply the acceleration with time you get the average speed.
Answer:
The light wave has a longer wavelength and has the greater speed.
Explanation:
light has a far more greater speed than sound. The speed of sound in air is about 343m/s while that of light is around 
wavelength (λ) =
since the frequencies of sound and light are same from the question, the wavelength would depend on the magnitude of their velocities. Light with a higher speed would have a longer wavelength.
