All categories

3 years ago

If your friend asked, "Why are plastics good insulators?" you would reply:

Physics

2 answers:

Stella [2.4K]3 years ago

8 0

I would read Choice #2 to him, enunciating clearly.

omeli [17]3 years ago

4 0

Explanation:

Insulators are materials that do no allow the flow of electric current inside it. The difference between conductors and insulators is that conductors have free electrons while insulators do not have. Plastic is a good insulator.

This is because materials like plastics do not have any loosely bound electrons in their outer shell making it difficult, if not impossible, for electrons to move between atoms.

Hence, the correct option is (2).

You might be interested in

A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 5.0 m/s2. Secret agent Austin Powers jumps on ju

denpristay [2]

Answer:

a) $h=250\ m$

b) $\Delta h=0.0835\ m$

Explanation:

Given:

upward acceleration of the helicopter, $a=5\ m.s^{-2}$

time after the takeoff after which the engine is shut off, $t_a=10\ s$

Maximum height reached by the helicopter:

using the equation of motion,

$h=u.t+\frac{1}{2} a.t^2$

where:

u = initial velocity of the helicopter = 0 (took-off from ground)

t = time of observation

$h=0+0.5\times 5\times 10^2$

$h=250\ m$

time after which Austin Powers deploys parachute(time of free fall), $t_f=7\ s$

acceleration after deploying the parachute, $a_p=2\ m.s^{-2}$

height fallen freely by Austin:

$h_f=u.t_f+\frac{1}{2} g.t_f^2$

where:

$u=$ initial velocity of fall at the top = 0 (begins from the max height where the system is momentarily at rest)

$t_f=$ time of free fall

$h_f=0+0.5\times 9.8\times 7^2$

$h_f=240.1\ m$

Velocity just before opening the parachute:

$v_f=u+g.t_f$

$v_f=0+9.8\times 7$

$v_f=68.6\ m.s^{-1}$

Time taken by the helicopter to fall:

$h=u.t_h+\frac{1}{2} g.t_h^2$

where:

$u=$ initial velocity of the helicopter just before it begins falling freely = 0

$t_h=$ time taken by the helicopter to fall on ground

$h=$ height from where it falls = 250 m

now,

$250=0+0.5\times 9.8\times t_h^2$

$t_h=7.1429\ s$

From the above time 7 seconds are taken for free fall and the remaining time to fall with parachute.

remaining time,

$t'=t_h-t_f$

$t'=7.1428-7$

$t'=0.1428\ s$

Now the height fallen in the remaining time using parachute:

$h'=v_f.t'+\frac{1}{2} a_p.t'^2$

$h'=68.6\times 0.1428+0.5\times 2\times 0.1428^2$

$h'=9.8165\ m$

Now the height of Austin above the ground when the helicopter crashed on the ground:

$\Delta h=h-(h_f+h')$

$\Delta h=250-(240.1+9.8165)$

$\Delta h=0.0835\ m$

5 0

3 years ago

Which material is used to reduce friction ?

Iteru [2.4K]

Answer:MOST COMMON METHOD IS USING A LUBRICANT -

A lubricant is a substance, usually organic, introduced to reduce friction between surfaces in ... medical examination. It is mainly used to reduce friction and to contribute to a better and efficient functioning of a mechanism. ... For lubricant base oil use, the vegetable derived materials are preferred

OTHER METHODS-

There are a number of ways to reduce friction:

Make the surfaces smoother. ...

Lubrication is another way to make a surface smoother.

Make the object more streamlined.

Reduce the forces acting on the surfaces.

Reduce the contact between the surfaces.

PLEASE DO MARK ME AS THE BRAINLIEST :)

6 0

3 years ago

1. Does the validity of the principle of conservation of momentum depend on the validity of Newton's 3rd law of motion?

OverLord2011 [107]

I truly believe so, that’s a definite yes

8 0

4 years ago

Where does all of this energy come from

Amiraneli [1.4K]

Answer: All of our energy comes from the sun, which is our nearest star. The sun sends out huge amounts of energy through its rays every day. We call this energy solar energy or radiant energy. Without the sun, life on earth would not exist, since our planet would be totally frozen.

6 0

3 years ago

An interplanetary spacecraft is moving at

mixer [17]

The awnser is. 1728000 kilometers

7 0

3 years ago

Read 2 more answers