Explain what it means when we say a substance is magnetic.


Discuss the relationship between electric and magnetic fields.


Which types of wires (cooper, aluminum, or string) are ferromagnetic metals?​

Answer:

36 m/s

Explanation:

t = 3.6s

u = 0m/s

a = +g = 10m/s²

v = ?

using,

v = u + at

v = 0 + 10(3.6)

v = 36 m/s

Since we are sitting in the bus, our current system is the bus

If any object outside our current system moves, we might think that our system has started moving

We are given the choices:

Passenger moving to the back of the bus: This passenger is moving in our current system. So, his movement will not make us think that the bus is moving

The bus driver turns to look through the windshield: The driver is part of our system and is moving moving within the system. So, we wont think that the bus is moving

A car in the next lane: This car is outside our current system and if it moves, we might think that our current system (the bus) has started moving

Therefore, the movement of a car in the next lane will make us think that the bus is moving

Answer: the focal length of the CCl4-glass combination is 102.31 cm

Explanation:

Given that;

Index of refraction n1 = 1.55

carbon tetrachloride (CCl4), which has n2 = 1.46

radii of curvature for its surfaces R1 = 4.6cm and R2 = 9.20 cm

the focal length of the CCl4-glass combination = ?

we can determine the focal length using the Formula;

1/f = ( n1 - n2) ( 1/R1 - 1/R)

so we substitute in our values

1/f = ( 1.55 - 1.46 ( 1/4.6 - 1/9.20)

1/f = 0.09 × 0.1086

1/f = 0.009774

f = 1 / 0.009774

f = 102.31 cm

Therefore the focal length of the CCl4-glass combination is 102.31 cm

Answer:

Explanation:

Step one:

given data

mass of bullet m1=25g= 0.025kg

initial velocity of bullet u1=240m/s

mass of block m2=?

initial velocity of bullet u2 of block=0m/s

final velocity of the system after impact v= 27m/s

Required; the mass of the block m2

Step two:

applying the conservation of linear moment/elastic collision we have

m1u1+m2u2=v(m1+m2)

substituting we have

0.025*240+m2*0=27(0.025+m2)

6=0.675+27m2

6-0.675=27m2

5.325=27m2

divide both sides by 27

m2=5.325/27

m2=0.197

m2=0.2kg approx.

Answer: The rate at which an object moves towards a target is Speed

Explanation:

Rate is something that tells us amount of solmething that changes in one unit of time.

Speed is defined as the measure of the rate of movement of a body expressed either as the distance travelled divided by the time taken.

Arc is defined as the apparent path described above and below the horizon taken up by a celestial body.

Force is defined as a push or pull upon an object resulting from the object's interaction with another object.

Trajectory is defined as the path followed by an object moving under the action of given force.

Answer:

distance i think

Explanation:

Answer:

50,000N

Explanation:

According to Newton's second law of motion;

Net Force = Mass * acceleration

Given

Mass = 5000kg

Let the acceleration = 10m/s²

Net force = 5000 * 10

Net force = 50,000N

Hence the net force acting on the bus is 50000N

Answer:

Option A. 3 m/s

Explanation:

From the question given above, the following data were obtained:

Mass of cart = 4 Kg

Momentum of cart = 12 kg•m/s.

Velocity of cart =?

Momentum is simply defined as the product of mass and velocity. Mathematically, it is expressed as:

Momentum = mass × velocity

Thus, we can obtain the velocity of the cart by using the above equation as illustrated below:

Mass of cart = 4 Kg

Momentum of cart = 12 kg•m/s.

Velocity of cart =?

Momentum = mass × velocity

12 = 4 × velocity

Divide both side by 4

Velocity of cart = 12 / 4

Velocity of cart = 3 m/s

Therefore, the velocity of the cart is 3 m/s

Answer:

448m/s

Explanation:

The speed of the wave with a given wavelength and frequency can be calculated using the formula:

λ = v/f

Where;

λ = wavelength (m)

v = speed of wave (m/s)

f = frequency of wave (Hz)

In this question, λ = 2.59 metres, f = 173 Hz, v = ?

λ = v/f

v = λ × f

v = 2.59 × 173

v = 448.07m/s

To the nearest whole number, 448.07 can be written as 448

Hence, the speed of the wave (v) is 448m/s.

Answer:

What is the speed of a wave that has a frequency of 173 Hz and a wavelength of 2.59 meters? Express your answer to the nearest whole number.

448

 m/s

Explanation:

Answer:

a. 77.9 nT

Explanation:

Given;

average value of the electromagnetic wave, E = 0.724 W/m^2

The average value of a Poynting vector is given by;

[tex]S = \frac{1}{2\mu_o} *E_oB_o\\\\But, E_o = cB_o\\\\S = \frac{1}{2\mu_o} *cB_o^2\\\\cB_o ^2= 2\mu_o S\\\\B_o^2 = \frac{2\mu_o S}{c}\\\\B_o = \sqrt{ \frac{2\mu_o S}{c}} \\\\B_o = \sqrt{ \frac{2(4\pi*10^{-7}) (0.724)}{3*10^8}}\\\\B_o = 7.79*10^{-8} \ T\\\\B_o = 77.9*10^{-9} \ T\\\\B_o = 77.9 \ nT[/tex]

Therefore, the maximum value of the magnetic field in the wave is 77.9 nT.

Answer:

A I think : )

Explanation:

Answer:

B, which is why ice skaters often keep their arms close to their body when doing spins and jumps to minimize resistance.

Answer:

The options are

A. Older rocks are commonly remitted over huge regions

B. Older rocks have been uplifted and eroded away

C. Large parts of the continent are subducted deep within the mantle

D. Parts of the continent have been added by the accretion of tectonic terraces.

The answer is D. Parts of the continent have been added by the accretion of tectonic terraces.

The major reason why the age of the oldest rocks can vary from one part of the continent to another is that parts of continent have been added by the accretion of tectonic terraces.

Answer:

Evaporation from oceans = 460,000 km³

Explanation:

Given:

Precipitation on oceans = 420,000 km³

Precipitation on land = 130,000 km³

Evaporation from land = 90,000 km³

Find:

Evaporation from oceans

Computation:

Evaporation from oceans = Precipitation on oceans + Precipitation on land - Evaporation from land

Evaporation from oceans = 420,000 km³ + 130,000 km³ - 90,000 km³

Evaporation from oceans = 460,000 km³

Answer:ccccccC

Explanation:okay

Answer:

2

Explanation:

there are 2 significant figures in there

Answer:

-7/19

Explanation:

Answer: 117.6N

Explanation:

By the second Newton's law, we know that:

F = m*a

F = force

m = mass

a = acceleration

We know that in the surface of the Earth, the gravitational acceleration is g = 9.8m/s^2.

Then we just can input that acceleration in the above equation, and also replace m by 12kg, and find that the force due the gravity is:

F = 12kg*9.8m/s^2 = 117.6N

Answer:

d = 105 m

Explanation:

Speed of a car, v = 21 m/s

We need to find the distance traveled by the dar during those 5 s before it stops. Let the distance is d. It can be calculated as :

d = v × t

d = 21 m/s × 5 s

d = 105 m

So, it will cover 105 m before it stops.

Answer:

45 kg is the mass of a table that weights 441 newton.

Answer:

45 kg

__________________________________________________________

Explanation:

We are given:

weight of the object = 441 N

Solving for the mass of the object:

We know that the weight of an object is the force applied by gravity to pull it towards the ground. So, we can say that:

Weight = Mg

[where M is the mass of the object and g is the gravitational constant]

replacing the variables with given values

441 = M(9.8)                                                     [since g = 9.8 m/s²]

Dividing both sides by 9.8

M = 441 / 9.8

M = 45 kg

Hence, the object has a mass of 45 kg

Answer:

c) 1.0 kg

Explanation:

The mass of the stick will be located at the centre of the metre rule. Since the rock is located 0.25m from the pivot, the mass of the meter rule is also 0.25m to the Right of the support

According to law of moment

Sum of clockwise moment = sum of anti clockwise moments

Clockwise moment = M×0.25(mass of metre rule is M)

CW moment = 0.25M

Anti clockwise moment = 0.25×1

ACW moments = 0.25kgm

Equate;

0.25M = 0.25

M = 0.25/0.25

M = 1.0kg

Hence the mass of the metre rule is 1.0kg

Answer:

wind energy can have adverse environmental impacts by, including the potential to reduce, fragment, or degrade habitat for wildlife, fish, and plants.

Answer:

Wind energy is better than fossil fuels in that it dosen't require the extraction of a limited resource or the release of carbon dioxide, but the manufacturing of the turbines uses materials that are harmful to the enviroment and the nonrecyclable turbine blades will inevitably end up in landfils. In conclusion, wind energy has its problems, but it is still better than most of the nonrenewable alternatives.

Explanation:

Answer:

The displacement of the car after 6s is 43.2 m

Explanation:

Given;

velocity of the car, v = 12 m/s

acceleration of the car, a = -1.6 m/s² (backward acceleration)

time of motion, t = 6 s

The displacement of the car after 6s is given by the following kinematic equation;

d = ut + ¹/₂at²

d = (12 x 6) + ¹/₂(-1.6)(6)²

d = 72 - 28.8

d = 43.2 m

Therefore, the displacement of the car after 6s is 43.2 m

Answer:

F = 1.8 KN

Explanation:

Given that the spacecraft is 2.00 Earth radii above the Earth's surface, the force of Earth's gravity on it can be determined by;

F = [tex]\frac{GMm}{(R + h)^{2} }[/tex]

Where: F is the force, G is the universal gravitation constant, M is the mass of the earth, m is the mass of the spacecraft, and R is the radius of the earth and h is the distance of the spacecraft to the surface of the earth.

G = 6.67 x [tex]10^{-11}[/tex] N[tex]m^{2}[/tex][tex]kg^{-2}[/tex], M = 5.972 x [tex]10^{24}[/tex] kg, m = 1650 kg, R = 6371 km, h = (2.0 x 6371 km) = 12742 km.

Thus,

F = [tex]\frac{6.67*10^{-11}*5.972*10^{24} *1650 }{(6371*10^{3}+12742*10^{3}) ^{2} }[/tex]

  = [tex]\frac{6.5725*10^{17} }{(19113000)^{2} }[/tex]

  = 1799.17

F = 1.8 KN

The force of the Earth's gravity on the spacecraft is 1.8 KN.

Initial velocity of the object (u) = 4.8 m/s

Final velocity of the object (v) = 15.6 m/s

Acceleration of the object (a) = 0.9 m/s²

By using equation of motion, we get:

[tex] \bf \longrightarrow v = u + at \\ \\ \rm \longrightarrow 15.6 = 4.8 + 0.9t \\ \\ \rm \longrightarrow 15.6 - 4.8 = 4.8 - 4.8 + 0.9t \\ \\ \rm \longrightarrow 10.8 = 0.9t \\ \\ \rm \longrightarrow 0.9t = 10.8 \\ \\ \rm \longrightarrow \dfrac{0.9}{0.9} t = \dfrac{10.8}{0.9} \\ \\ \rm \longrightarrow t = 12 \: s[/tex]

[tex] \therefore [/tex] Time taken by the object (t) = 12 s

Answer:

Explanation:

Step one:

given data

mass of cable= 4lb/ft

mass of coal= 1000lb

dept of mine= 700ft

Step two:

Required

the work-done to lift the coal and the rope combined

Work-done to lift coal

Wc=1000*700= 700,000 lb-ft

Work-done to lift rope

[tex]Wr=\int\limits^{700} _0 {4(700-y)} \, dx \\\\Wr=4(700y-\frac{1}{2}y^2 )\limits^{700}_0[/tex]

substitute y=700 we have, since y=0 will result to 0

[tex]Wr=4(700*700-\frac{1}{2}*700^2 )\\\\Wr=4(490000-245000)\\\\Wr=4(245000)\\\\Wr=980000ft-lbs[/tex]

Answer:

v = 5.24 m/s

Explanation:

Given that,

No of spokes of a Ferris wheel = 60

The diameter of a wheel, d = 100 m

Radius, r = 50 m

It makes one rotation every 60 seconds.

We need to find the speed of the passengers when the Ferris wheel is rotating at this rate. Let it is v. It can be calculated as follows :

[tex]v=r\omega\\\\=\dfrac{2\pi r }{T}\\\\=\dfrac{2\pi \times 50 }{60}\\\\v=5.235\ m/s[/tex]

or

v = 5.24 m/s

So, the speed of the passengers is 5.24 m/s. Hence, the correct option is (A).

Answer:

i. F =  1.3 x [tex]10^{-7}[/tex] N

ii. The direction of the force of attraction exerted by the proton on the electron is towards the itself (i.e a pull).

Explanation:

Since the given charges are opposite, then the force of attraction is experienced. The force of attraction between the two charges can be determined by:

F = [tex]\frac{kq_{1} q_{2} }{d^{2} }[/tex]

where F is the force, k is the constant, [tex]q_{1}[/tex] is the charge of the electron, [tex]q_{2}[/tex] is the charge on the proton, and d is the distance between them.

So that; k = 9.0 x [tex]10^{9}[/tex] N[tex]m^{2}[/tex][tex]C^{-2}[/tex] , [tex]q_{1}[/tex] = 1.6 x [tex]10^{-19}[/tex] C, [tex]q_{2}[/tex] = 1.6 x

Thus,

F = [tex]\frac{9.0*10^{9}*1.6*10^{-19}*1.6*10^{-19} }{(4.2*10^{-11}) ^{2} }[/tex]

  = [tex]\frac{2.304*10^{-28} }{1.764*10^{-21} }[/tex]

  = 1.3061 x [tex]10^{-7}[/tex]

F = 1.3 x [tex]10^{-7}[/tex] N

The force between the charges is 1.3 x [tex]10^{-7}[/tex] N.

ii. The direction of the force of attraction exerted by the proton on the electron is towards the itself.

Answer:

a) The perimeter of the rectangle is 29.4 centimeters.

b) The uncertainty in its perimeter is 0.8 centimeters.

Explanation:

a) From Geometry we remember that the perimeter of the rectangle ([tex]p[/tex]), measured in centimeters, is represented by the following formula:

[tex]p = 2\cdot (w+l)[/tex] (1)

Where:

[tex]w[/tex] - Width, measured in centimeters.

[tex]l[/tex] - Length, measured in centimeters.

If we know that [tex]w = 6.4\,cm[/tex] and [tex]l = 8.3\,cm[/tex], then the perimeter of the rectangle is:

[tex]p = 2\cdot (6.4\,cm+8.3\,cm)[/tex]

[tex]p = 29.4\,cm[/tex]

The perimeter of the rectangle is 29.4 centimeters.

b) The uncertainty of the perimeter ([tex]\Delta p[/tex]), measured in centimeters, is estimated by differences. That is:

[tex]\Delta p = 2\cdot (\Delta w + \Delta l)[/tex]  (2)

Where:

[tex]\Delta w[/tex] - Uncertainty in width, measured in centimeters.

[tex]\Delta l[/tex] - Uncertainty in length, measured in centimeters.

If we know that [tex]\Delta w = 0.2\,cm[/tex] and [tex]\Delta l = 0.2\,cm[/tex], then the uncertainty in perimeter is:

[tex]\Delta p = 2\cdot (0.2\,cm+0.2\,cm)[/tex]

[tex]\Delta p = 0.8\,cm[/tex]

The uncertainty in its perimeter is 0.8 centimeters.

Answer:

Explanation:

The weight of the object can be found by using the formula

[tex]f = \frac{w}{d} \\ [/tex]

w is the workdone

d is the distance

From the question we have

[tex]f = \frac{62500}{25} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

D. The carbon dioxide levels in the atmosphere began increasing rapidly around 1950.

Explanation:

Study Island

The carbon dioxide levels in the atmosphere began increasing rapidly around 1950. Therefore, the correct option is option D.

One carbon atom is covalently doubly connected to the two oxygen atoms in each of the molecules that make up carbon dioxide. At room temperature, it exists as a gas.

In the atmosphere, carbon dioxide serves as a greenhouse gas because it absorbs infrared radiation despite being transparent to visible light. It has increased from which was before values of 280 ppm to be a gas in the atmosphere in the Stratosphere at 431 parts per thousand, or roughly 0.04% by volume. The carbon dioxide levels in the atmosphere began increasing rapidly around 1950. This statement is true.

Therefore, the correct option is option D.

To know more about carbon dioxide, here:

https://brainly.com/question/9630194

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its the the first one u said