Speed has only magnitude and no direction.
Answer:
Nylon fibres
Explanation:
Nylon fibres are synthetic polymers made of repeating units linked by amide links. It is a thermoplastic silky material which can be remoulded in any shape.
Nylon fibres have the property of strong elastic and light in weight that is why used for making ropes, combat uniforms, and parachutes. Nylon Fibres are also lustrous and easy to wash so widely used in textile industry for making swimwear, track pants, shorts, and draperies.
Hence, the correct answer is "Nylon fibres".
Answer:
(a): 
(b): 
(c): 
Explanation:
Given that an electron revolves around the hydrogen atom in a circular orbit of radius r = 0.053 nm = 0.053
m.
Part (a):
According to Coulomb's law, the magnitude of the electrostatic force of interaction between two charged particles of charges
and
respectively is given by

where,
= Coulomb's constant = 
= distance of separation between the charges.
For the given system,
The Hydrogen atom consists of a single proton, therefore, the charge on the Hydrogen atom, 
The charge on the electron, 
These two are separated by the distance, 
Thus, the magnitude of the electrostatic force of attraction between the electron and the proton is given by

Part (b):
The gravitational force of attraction between two objects of masses
and
respectively is given by

where,
= Universal Gravitational constant = 
= distance of separation between the masses.
For the given system,
The mass of proton, 
The mass of the electron, 
Distance between the two, 
Thus, the magnitude of the gravitational force of attraction between the electron and the proton is given by

The ratio
:

The solution for this problem is:
r = [(2.90 + 0.0900t²) i - 0.0150t³ j] m/s²
this is for t in seconds and r in meters
v = dr/dt = [0.180t i - 0.0450t² j] m/s²
tan(-36.0º) = -0.0450t² / 0.180t
0.7265 = 0.25t
t = 2.91 s is the velocity vector of the insect
The Paleozoic era spanned from the Cambrian to the Permian and ended with a mass extinction at the end of the Permian. Geologists are still unsure of the cause but the theories include a meteorite impact or a massive volcanic event in Siberia or a combination of both. This could be a possible cause of the melting of the late Paleozoic ice sheets.