Reflection from such a rough surface is called diffuse reflection and appears matte
These are known as balanced forces because they will not change the motion of the object, and it will remain at rest unless forces become unbalanced- meaning they would be unequal and not opposing.
F = ma = -kx
a = 9.81 m/s²
k = 3430 N/m
m = 70 kg
x = - ma/ k = 0.2m
Answer:
"It will be more than the speed of sound waves in air at 20*C and water at 20*C."
Explanation:
Speed of sound in a medium depends upon the density and elasticity of the medium.
If the elasticity of a medium is greater and the density of that medium is lower, sound will travel faster. Although density is also a factor but the major factor is Elasticity.
Hence, sound travel faster in solids than in liquids and even slower in gases due to elasticity difference.

That is why the speed of sound in glass will be more than the speed of sound waves in air at 20*C and water at 20*C.
Answer:
b) the reflected pulse returns inverted while the transmitted pulse is right side up
Explanation:
A wave pulse traveling to the right along a thin cord reaches a discontinuity where the rope becomes thicker and heavier.
Then, as far as orientation of reflected and transmitted pulses are concerned the reflected pulse returns inverted while the transmitted pulse is right side up.
Hence the correct answer is b.