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2 years ago

Which type of electromagnetic radiation is commonly used for long-distance communications?

Physics

1 answer:

Citrus2011 [14]2 years ago

5 0

Answer:

B. Radio waves

Explanation:

Radio waves are transmitted easily through air. They do not cause damage if absorbed by the human body, and they can be reflected to change their direction. These properties make them ideal for communications.

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Lightning bolts can carry currents up to approximately 20 kA. We can model such a current as the equivalent of a very long, stra

GalinKa [24]

Answer:

how large a magnetic field would you experience = 8.16 x 10∧-4T

Explanation:

I = 20KA = 20,000A

r = 4.9 m

how large a magnetic field would you experience = u.I/2πr

how large a magnetic field would you experience = (4π x10∧-7) × 20000/2π × 4.9

how large a magnetic field would you experience = 8.16 x 10∧-4T

4 0

3 years ago

Read 2 more answers

Ignoring air resistance, if a 20 kg ball and a 400 kg crate were both dropped from the

masya89 [10]

The crate’s acceleration is gravity= 9.81m/s^2
The ball’s acceleration is also gravity=9.81m/s^2

8 0

3 years ago

A person of mass 70 kg stands at the center of a rotating merry-go-round platform of radius 2.9 m and moment of inertia 900 kg⋅m

Cloud [144]

Explanation:

It is given that,

Mass of person, m = 70 kg

Radius of merry go round, r = 2.9 m

The moment of inertia, $I_1=900\ kg.m^2$

Initial angular velocity of the platform, $\omega=0.95\ rad/s$

Part A,

Let $\omega_2$ is the angular velocity when the person reaches the edge. We need to find it. It can be calculated using the conservation of angular momentum as :

$I_1\omega_1=I_2\omega_2$

Here, $I_2=I_1+mr^2$

$I_1\omega_1=(I_1+mr^2)\omega_2$

$900\times 0.95=(900+70\times (2.9)^2)\omega_2$

Solving the above equation, we get the value as :

$\omega_2=0.574\ rad/s$

Part B,

The initial rotational kinetic energy is given by :

$k_i=\dfrac{1}{2}I_1\omega_1^2$

$k_i=\dfrac{1}{2}\times 900\times (0.95)^2$

$k_i=406.12\ rad/s$

The final rotational kinetic energy is given by :

$k_f=\dfrac{1}{2}(I_1+mr^2)\omega_1^2$

$k_f=\dfrac{1}{2}\times (900+70\times (2.9)^2)(0.574)^2$

$k_f=245.24\ rad/s$

Hence, this is the required solution.

5 0

2 years ago

What do work and energy have in common

spayn [35]

Energy and Work have the same unit of measurement which is Joules in SI units.

Explanation:

A Joule of Work is said to be done on an object when energy is transferred to that particular object.
If two objects are involved, when one object transfers energy onto the second, a joule of work is said to be done by the first object.
Work is also the application of force on an object over a distance. So Work = Force × Displacement
Energy is neither created nor destroyed. It is in 2 forms - kinetic and potential.
Kinetic energy is defined as the energy of a moving object while potential energy is known as the energy that is stored within an object.
Kinetic Energy = 1/2 × mass × (velocity)²
Potential Energy = mass × acceleration due to gravity × height
Both energy and work are measured in Joules.

3 0

3 years ago

How long did the trip from camp wood to the pacific ocean and back again take?

maria [59]

The trip from Camp Wood to the Pacific Ocean and back again took 1.5 years to complete.

The Lewis and Clark Expedition from May 1804 to September 1806, also known as the Corps of Discovery Expedition, was the first American expedition to cross what is now the western portion of the United States.

6 0

3 years ago