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2 years ago

How does the stratosphere protect us?

Physics

1 answer:

Rudik [331]2 years ago

4 0

<span>It acts as a sunscreen to </span>protect us<span> against UV radiation. </span>

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particle of mass 59 g and charge 51 µC is released from rest when it is 32 cm from a second particle of charge −14 µC. Determine

AleksAgata [21]

Answer:

The initial acceleration of the 59g particle is $1062.7\frac{m}{s^{2}}$

Explanation:

Newton's second laws relates acceleration (a), net force(F) and mass (m) in the next way:

$F=ma$ (1)

We already know the mass of the particle so we should find the electric force on it to use on (1), the magnitude of the electric force between two charged objects by Columb's law is:

$F=k\frac{\mid q_{1}q_{2}\mid}{r^{2}}$

with q1 and q2 the charge of the particles, r the distance between them and k the constant $k=9.0\times10^{9}\,\frac{Nm^{2}}{C^{2}}$ . So:

$F=(9.0\times10^{9})\frac{\mid (51\times10^{-6})(-14\times10^{-6})\mid}{0.32^{2}}$

$F=62.7 N$

Using that value on (1) and solving for a

$a=\frac{F}{m}=\frac{62.7}{0.059}=1062.7\frac{m}{s^{2}}$

4 0

3 years ago

Wire sizes are often reported using the AWG (American Wire Gauge) system in which smaller diameter wires are said to be of highe

NISA [10]

Answer:

Explanation:

24 - gauge wire , diameter = .51 mm .

Resistivity of copper ρ = 1.72 x 10⁻⁸ ohm-m

R = ρ l / s

1.72x 10⁻⁸ / [3.14 x( .51/2)² x 10⁻⁶ ]

= 8.42 x 10⁻² ohm

= .084 ohm

B ) Current required through this wire

= 12 / .084 A

= 142.85 A

C )

Let required length be l

resistance = .084 l

2 = 12 / .084 l

l = 12 / (2 x .084)

= 71.42 m

6 0

2 years ago

Read 2 more answers

Assume that the polymer material has a constant refractive index of 1.5. For light of 600nm wavelength at normal incidence, what

yaroslaw [1]

Answer:

Minimum thickness will be 100 nm

Explanation:

We have given refractive index is n = 1.5

Wavelength of the light incidence $\lambda$ = 600 nm

We have to find the smallest thickness of the film so that there will be minimum light reflect

For minimum thickness of non reflecting film

$t=\frac{\lambda }{4n}$ , here t is thickness, $\lambda$ is wavelength and n is refractive index

Putting all values $t=\frac{600}{4\times 1.5}=100nm$

So minimum thickness will be 100 nm

8 0

2 years ago

A sphere of volume 1.20×10−3m3 hangs from a cable. When the sphere is completely submerged in water, the tension in the cable is

KATRIN_1 [288]

Answer:

B = 62.9 N

Explanation:

This is an exercise on Archimedes' principle, where the thrust force equals the weight of the liquid

B = ρ g V

write the equilibrium equation

T + B -W = 0

B = W- T (1)

use the density to write the weight

ρ = m / V

m = ρ V

W = ρ g V

substitute in 1

B = m g -T

B = $\rho_{body}$ g V - T

To finish the calculation, the density of the material must be known, suppose it is steel \rho_{body} = 7850 kg / m³

calculate

B = 7850 9.8 1.20 10⁻³ - 29.4

B = 92.3 - 29.4

B = 62.9 N

4 0

2 years ago

To transform electrical energy into mechanical energy, the electromagnet in a

lidiya [134]

Answer:

Motors commonly contain a "commutator" which allows a magnetic field due to a loop of wire to always be in a say "clockwise or counterclockwise" direction even tho the loop of wire is rotating.

That means that magnetic field due to the surrounding magnets is always in the same direction, but the magnetic field due to the rotating loop of wire is continually changing so that it will always oppose the surrounding field which remains in a constant direction.

This is most easily seen in a "DC - direct current motor".

6 0

1 year ago