Any electromagnetic wave, like light or heat.
I was about to say: because people generally get comfortable with
what they think they know, and don't like the discomfort of being told
that they have to change something they're comfortable with.
But then I thought about it a little bit more, and I have a different answer.
"Society" might initially reject a new scientific theory, because 'society'
is totally unequipped to render judgement of any kind regarding any
development in Science.
First of all, 'Society' is a thing that's made of a bunch of people, so it's
inherently unequipped to deal with scientific news. Anything that 'Society'
decides has a lot of the mob psychology in it, and a public opinion poll or
a popularity contest are terrible ways to evaluate a scientific discovery.
Second, let's face it. The main ingredient that comprises 'Society' ... people ...
are generally uneducated, unknowledgeable, unqualified, and clueless in the
substance, the history, and the methods of scientific inquiry and reporting.
There may be very good reasons that some particular a new scientific theory
should be rejected, or at least seriously questioned. But believe me, 'Society'
doesn't have them.
That's pretty much why.
I believe that the best statement which explains why you can do this is C. <span>The extension cord is made of copper wire, which is a good conductor of electricity; however, it is covered with plastic, an insulator, which does not allow the electrical current to flow to you.
Copper is known to be one of the best conductors of electricity, and plastic can shield you from shock.
</span>
Answer:
V = 331.59m/s
Explanation:
First we need to calculate the time taken for the shell fire to hit the ground using the equation of motion.
S = ut + 1/2at²
Given height of the cliff S = 80m
initial velocity u = 0m/s²
a = g = 9.81m/s²
Substitute
80 = 0+1/2(9.81)t²
80 = 4.905t²
t² = 80/4.905
t² = 16.31
t = √16.31
t = 4.04s
Next is to get the vertical velocity
Vy = u + gt
Vy = 0+(9.81)(4.04)
Vy = 39.6324
Also calculate the horizontal velocity
Vx = 1330/4.04
Vx = 329.21m/s
Find the magnitude of the velocity to calculate speed of the shell as it hits the ground.
V² = Vx²+Vy²
V² = 329.21²+39.63²
V² = 329.21²+39.63²
V² = 108,379.2241+1,570.5369
V² = 109,949.761
V = √ 109,949.761
V = 331.59m/s
Hence the speed of the shell as it hits the ground is 331.59m/s
Answer:
a) 43.2 Jm⁻³
b) 0.0941 J
Explanation:
A = area of cross-section = 23 cm² = 23 x 10⁻⁴ m²
l = length of solenoid = 94.9 cm = 0.949 m
L = inductance of solenoid
N = Number of turns = 809
i = current = 9.70 A
Inductance is given as
L = μ₀ N² A l⁻¹
L = (12.56 x 10⁻⁷) (809)² (23 x 10⁻⁴) (0.949)⁻¹
L = 0.002
V = Volume = Al = (23 x 10⁻⁴) (0.949) = 21.8 x 10⁻⁴ m³
Energy density is given as
U = (0.5) L i² V⁻¹
U = (0.5) (0.002) (9.70)² (21.8 x 10⁻⁴)⁻¹
U = 43.2 Jm⁻³
b)
Total energy is given as
E = (0.5) L i²
E = (0.5) (0.002) (9.70)²
E = 0.0941 J
