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1 year ago

Which of the following strategies can help Earth's coal supply last longer?

Physics

2 answers:

ivanzaharov [21]1 year ago

7 0

D. Teach the public energy conservation

Xelga [282]1 year ago

4 0

Answer: D. Teach the public energy conservation

Coal is an efficient and inexpensive source of energy which provides a stable and large scale energy generation in the form of electrical and thermal energy. It is a type of fossil fuel which is most abundantly present. But it is also a non- renewable source of energy, and cannot be replenished after a single use. It is used as a source of generation of electricity, production of metallic objects, manufacturing of a liquid fuel, engines of local trains and for other purposes. As, it is a non- renewable resource it should be used in a sustainable way.

Hence, D. Teach the public energy conservation is the correct option.

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What is the resistance ofa wire made of a material with resistivity of 3.2 x 10^-8 Ω.m if its length is 2.5 m and its diameter i

Katarina [22]

R = 0.407Ω.

The resistance R of a particular conductor is related to the resistivity ρ of the material by the equation R = ρL/A, where ρ is the material resistivity, L is the length of the material and A is the cross-sectional area of the material.

To calculate the resistance R of a wire made of a material with resistivity of 3.2x10⁻⁸Ω.m, the length of the wire is 2.5m and its diameter is 0.50mm.

We have to use the equation R = ρL/A but first we have to calculate the cross-sectional area of the wire which is a circle. So, the area of a circle is given by A = πr², with r = d/2. The cross-sectional area of the wire is A = πd²/4. Then:

R =[(3.2x10⁻⁸Ω.m)(2.5m)]/[π(0.5x10⁻³m)²/4]

R = 8x10⁻⁸Ω.m²/1.96x10⁻⁷m²

R = 0.407Ω

5 0

1 year ago

A man climbs a ladder. Which two quantities can be used to calculate the energy stored of the man at the top of the ladder.

Dvinal [7]

Answer:The answer must be The weight of the man and the vertical distance moved.

Explanation: you calculate it by the force you applied times the distance you moved

8 0

1 year ago

A light ray just grazes the surface of the Earth (M = 6.0 × 10 24 kg, R = 6.4×10 6 m). Through what angle α is the light ray ben

grandymaker [24]

Answer:

(a). The deflection angle is $2.77\times10^{-9}\ rad$

(b). The deflection angle is $3.95\times10^{-4}\ rad$

(c). The deflection angle is $7.41\times10^{-1}\ rad$

Explanation:

Given that,

Mass of earth $M_{e}=6.0\times10^{24}\ kg$

Radius of earth $R_{e}=6.4\times10^{6}\ m$

Mass of white dwarf $M=2.0\times10^{30}\ kg$

Radius of white dwarf $R=1.5\times10^{7}\ m$

Mass of Neutron $M=3.0\times10^{30}\ kg$

Radius of neutron $R=1.2\times10^{4}\ m$

We need to calculate the deflection angle for earth

Using formula of angle

$\alpha=\dfrac{4G M}{c^2R}$

Where, R = radius

G = gravitational constant

M = mass

c = speed of light

Put the value into the formula

$\alpha=\dfrac{4\times6.67\times10^{-11}\times6.0\times10^{24}}{(3\times10^{8})^2\times6.4\times10^{6}}$

$\alpha=2.77\times10^{-9}\ rad$

The deflection angle is $2.77\times10^{-9}\ rad$

We need to calculate the deflection angle for white dwarf

Using formula of angle

$\alpha=\dfrac{4G M}{c^2R}$

Put the value into the formula

$\alpha=\dfrac{4\times6.67\times10^{-11}\times2.0\times10^{30}}{(3\times10^{8})^2\times1.5\times10^{7}}$

$\alpha=3.95\times10^{-4}\ rad$

The deflection angle is $3.95\times10^{-4}\ rad$

We need to calculate the deflection angle for neutron star

Using formula of angle

$\alpha=\dfrac{4G M}{c^2R}$

Put the value into the formula

$\alpha=\dfrac{4\times6.67\times10^{-11}\times3.0\times10^{30}}{(3\times10^{8})^2\times1.2\times10^{4}}$

$\alpha=7.41\times10^{-1}\ rad$

The deflection angle is $7.41\times10^{-1}\ rad$

Hence, This is the required solution.

3 0

2 years ago

(Double points) A mechanic used a wrench 0.6 meters long to loosen rusted lug nuts on a truck wheel. By standing on the end of t

Korolek [52]

Answer:

Torque, $\tau=588\ N-m$

Explanation:

It is given that,

Length of the wrench, l = 0.6 m

Mass of the wrench, m = 100 kg

We know that the torque applied by mechanic is given by :

$\tau=Fl$

$\tau=mgl$

$\tau=100\times 9.8\times 0.6$

$\tau=588\ N-m$

So, the torque applied by the mechanic is 588 N-m. Hence, this is the required solution.

3 0

2 years ago

A ball is thrown into the air and follows the parabolic path indicated by the dashed line. Use the arrows provided to indicate t

avanturin [10]

Answer:

Trajectory is the path of a projectile in air. Any tangential to the curve shows it velocity and the slope of the tangential line will be it acceleration.

Explanation:

5 0

1 year ago