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3 years ago

Why are electromagnets more useful than permanent magnets in many

Physics

2 answers:

Likurg_2 [28]3 years ago

5 0

Answer: Electromagnets can be turned on and off by controlling the current

Explanation:

Tasya [4]3 years ago

5 0

B. By controlling the current, electromagnets can be turned on and off

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A particle moving along the x-axis has its velocity described by the function vx =2t2m/s, where t is in s. its initial position

Nesterboy [21]

The position of the object at time t =2.0 s is 6.4 m.

Velocity vₓ of a body is the rate at which the position x of the object changes with time.

Therefore,

$v_x= \frac{dx}{dt}$

Write an equation for x.

$dx=v_xdt\\ x=\int v_xdt$

Substitute the equation for vₓ =2t² in the integral.

$x=\int v_xdt\\ =\int2t^2dt\\ =\frac{2t^3}{3} +C$

Here, the constant of integration is C and it is determined by applying initial conditions.

When t =0, x = 1. 1m

$x= \frac{2t^3}{3} +C\\ x_0=1.1\\ x= (\frac{2t^3}{3} +1.1)m$

Substitute 2.0s for t.

$x= (\frac{2t^3}{3} +1.1)m\\ =\frac{2(2.0)^3}{3} +1.1\\ =6.43 m$

The position of the particle at t =2.0 s is 6.4m

5 0

3 years ago

A spring stretches by 0.0208 m when a 3.39-kg object is suspended from its end. How much mass should be attached to this spring

sashaice [31]

Answer:

COMPLETE QUESTION

A spring stretches by 0.018 m when a 2.8-kg object is suspended from its end. How much mass should be attached to this spring so that its frequency of vibration is f = 3.0 Hz?

Explanation:

Given that,

Extension of spring

x = 0.0208m

Mass attached m = 3.39kg

Additional mass to have a frequency f

Let the additional mass be m

Using Hooke's law

F= kx

Where F = W = mg = 3.39 ×9.81

F = 33.26N

Then,

F = kx

k = F/x

k = 33.26/0.0208

k = 1598.84 N/m

The frequency is given as

f = ½π√k/m

Make m subject of formula

f² = ¼π² •(k/m

4π²f² = k/m

Then, m4π²f² = k

So, m = k/(4π²f²)

So, this is the general formula,

Then let use the frequency above

f = 3Hz

m = 1598.84/(4×π²×3²)

m = 4.5 kg

4 0

3 years ago

Please help me on this 1 assignment im giving 25 points GOOD LUCK!

kati45 [8]

Answer:

Explanation:

im sorry if this doesn't help but i think its A

3 0

3 years ago

Identify characteristics of energy from the Sun. Check all that apply.

-BARSIC- [3]

Almost all of the energy on Earth comes from the Sun

The energy in fossil fuels originally came from the Sun

Plants convert the energy

Explanation:

The sun is the ultimate source of energy on earth and even the whole of the solar system. The sun drives and powers all external processes on earth. It produces its energy from the nuclear fusion of lighter nuclei into heavier ones.

Almost all of the energy on earth comes from the sun. A few component of the energy on the surface comes from the internal heat engine.
The energy of fossil fuels originally came from the sun. This is because, plants stores the energy in the process of photosynthesis. When they die and the energy is not released, the energy is stored as fossil fuels.
Plants in the process of photosynthesis converts the energy. Here green plants combines carbon dioxide and water in the presence of sunlight.

Learn more:

Convection brainly.com/question/1140127

#learnwithBrainly

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3 years ago

When nasa launched the kepler spacecraft in 2009 what was its primary mission

DiKsa [7]

The Kepler mission is specifically designed to survey a portion of our region of the Milky Way galaxy to discover dozens of Earth-size planets in or near the habitable zone and determine how many of the billions of stars in our galaxy have such planets

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3 years ago