Two identical metal spheres A and B are in contact. Both are initially neutral. 1.0 X 1012 electrons are added to sphere A, then the two spheres are separated. Afterward, what is the charge of sphere A

Answer:

a commutator

Explanation:

Answer:

1666.7 ETB (birr)

833.3 ETB (birr)

2083.3 ETB (birr)

Explanation:

The first worker

5000*1/3=1666.7

The second worker

5000*1/6=833.3

The third worker

5000*5/12=2083.3

Hope this helps :) ❤❤❤

Answer:

3000 N

Explanation:

as we know that

pressure=force/area

so force=thurst

pressure=thurst/area

thyrst=pressure*area

pressure=150 Nm^-2

area=20m^2

so thurst=150*20=3000 N or 3*10^3 N

Answer:

4) three

Explanation:

Assuming you mean 1.365248×10⁷, 2% of that is:

0.02 (1.365248×10⁷) = 0.027305×10⁷

So the number is:

1.365248×10⁷ ± 0.027305×10⁷

We need to round this number so that there is uncertainty only in the last digit.

1.37×10⁷ ± 0.03×10⁷

There are three significant figures in 1.37.

Answer:

Stopping distance = 40m

Explanation:

Given the following :

Initial speed of vehicle before applying brakes = 72km/hr

Converting km/hr to m/s:

72km/hr = [(72 * 1000)m] / (60 * 60)

72km/hr = 72,000m / 3600s

72km/hr = 20m/s

Deceleration after applying brakes (-a) (negative acceleration) = - 5m/s^2

From the 3rd equation of motion:

v^2 = u^2 + 2as

Where v = final Velocity ; u= Initial Velocity ; a = acceleration and s = distance

Final velocity when the car stops will be 0

Therefore ;

v^2 = u^2 + 2as

0 = 20^2 + 2(-5)(s)

0 = 400 - 10s

10s = 400

s = 400/10

s = 40m

Therefore, the stopping distance of the car = 40 meters

Answer:

a) 8.89 s

b) 50.6 m/s

c) 25.3 m/s

Explanation:

d = 225 m

v₀ = 0 m/s

a = (-3.5i + 4.5j) m/s²

First, find the magnitude of the acceleration.

a = √((-3.5)² + (4.5)²) m/s²

a = 5.7 m/s²

a) Find t

Δx = v₀ t + ½ at²

225 m = (0 m/s) t + ½ (5.7 m/s²) t²

t = 8.89 s

b) Find v

v² = v₀² + 2aΔx

v² = (0 m/s)² + 2 (5.7 m/s²) (225 m)

v = 50.6 m/s

c) Find v_avg

v_avg = Δx / t

v_avg = 225 m / 8.89 s

v_avg = 25.3 m/s

Or, for constant acceleration:

v_avg = (v₀ + v) / 2

v_avg = (0 m/s + 50.6 m/s) / 2

v_avg = 25.3 m/s

Answer:

t=7.25 sec

Explanation:

840=16t'2,

Answer:

(a) 1900 kg m²

(b) 8950 Nm

Explanation:

(a) The moment of inertia of a rod about its end is I = ⅓mL².

For 3 rods of mass m = 135 kg and length L = 3.75 m, the total moment of inertia is:

I = 3 (⅓ (135 kg) (3.75 m)²)

I = 1900 kg m²

(b) Net torque = moment of inertia × angular acceleration

∑τ = Iα

First, find the angular acceleration.

ω₀ = 0 rad/s

ω = 6.0 rev/s (2π rad/rev) = 37.7 rad/s

t = 8.0 s

α = (37.7 rad/s − 0 rad/s) / 8.0 rad/s = 4.71 rad/s²

∑τ = Iα

∑τ = (1900 kg m²) (4.71 rad/s²)

∑τ = 8950 kg m² / s²

∑τ = 8950 Nm

Explanation:

It is given that,

The angle of projection is 60 degrees

Initial velocity of the ball is 120 m/s

We need to find the time taken to get to the maximum height and the time of flight.

Time taken to reach the maximum height is given by :

[tex]T=\dfrac{u^2\sin^2\theta}{2g}[/tex]

g is acceleration due to gravity

[tex]T=\dfrac{(120)^2\times \sin^2(60)}{2\times 10}\\\\T=540\ s[/tex]

(ii) Time of flight,

[tex]t=\dfrac{2u\sin\theta}{g}[/tex]

So,

[tex]t=\dfrac{2\times 120\times \sin(60)}{10}\\\\t=20.78\ s[/tex]

Hence, this is the required solution.

Answer:

2.38 m/s

Explanation:

Momentum is conserved:

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

After the collision, they move at the same speed, so v₁ = v₂ = v.

m₁u₁ + m₂u₂ = (m₁ + m₂) v

Plugging in numbers:

(115 kg) u₁ + (133 kg) (-1.59 m/s) = (115 kg + 133 kg) (0.250 m/s)

u₁ = 2.38 m/s

Answer:

we need it to work and without it we dont have strength to do anything

Answer:

energy is important to all living organisms. energy for producers comes from the sun, and energy for consumers comes from other living organisms. the abundance of energy available for organisms impacts the population.

Answer:

F = 57.6 N

Explanation:

An electrostatic force is either a force of attraction or repulsion between two charges. When the two charges are like charges, the force is that of repulsion. But when they are of opposite charges, then the force between them is an attractive force.

A proton has a charge of 1.6 × [tex]10^{-19}[/tex] C. The electrostatic force can be determined by;

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

Where: k is a constant, [tex]q_{1}[/tex] is the first charge, [tex]q_{2}[/tex] is the second charge, and r is the distance between the charges.

But, [tex]q_{1}[/tex] =  [tex]q_{2}[/tex] = 1.6 × [tex]10^{-19}[/tex] C, k = 9 × [tex]10^{9}[/tex] N[tex]m^{2}[/tex]/[tex]C^{2}[/tex], r = 2 × [tex]10^{-15}[/tex] m. Therefore;

F = [tex]\frac{9*10^{9}*1.6*10^{-19} *1.6*10^{-19} }{(2*10^{-15}) ^{2} }[/tex]

= [tex]\frac{2.304*10^{-28} }{4*10^{-30} }[/tex]

= 57.6 N

The electrostatic force between the protons is 57.6 N.

Answer:

B. The dentist uses X-ray radiography, which takes too short a time to cause those problems.

Explanation:

The statement B would best inform Sally of the level of risk. The dentist uses X-ray radiography, which takes too short a time to cause those problems and risk.

X-ray imaging provides images of human internal organs. The photos depict your body parts in various colors of black and white.

Because various tissues absorb varying quantities of radiation, this is the case. Because calcium absorbs the most x-rays, bones appear white.

When X-ray radiation passes into our bodies, it damages molecular structures and may cause injury.

Human cells are damaged by extremely high doses of radiation, as indicated by skin burns, hair loss, and an increased risk of cancer.

Sally is concerned about the X-ray images her dentist plans to take of her teeth. She has read that X-rays can cause tissue effects, such as skin reddening and hair loss.

The statement B would best inform Sally about the level of risk. The dentist uses X-ray radiography, which takes too short a time to cause those problems and risk.

Hence, statement B would best inform Sally about the level of risk.

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Answer:

1) a.  52.41 m/s

b. The skier will be going 15.35 m/s slower

2)  103.68 m

3) 35,127 J

4) a.  88.825 kJ

(b) 16.36 %

5) 3,071.12 J

Explanation:

1) a. The given height of the hill, h = 140.0 m

The mass of the skier at the top of the hill, m = 85.0 kg

The acceleration due to gravity, g = 9.81 m/s²

The initial potential energy, P.E of the skier = m×g×h = 85.0×140.0×9.81 = 116739 J

From the principle of conservation of energy, we have;

The potential energy, P.E. lost = The gain in kinetic energy, K.E.

m×g×h = 1/2×m×v²

116739 J = 1/2×85.0×v²

v² = 116739/(1/2*85.0)= 2746.8 m²/s²

v = √(2746.8 m²/s²) = 52.41 m/s

b. From 70 m up, we have;

The initial potential energy, P.E., of the skier is now = 85.0×70×9.81 = 58,369.5 J

The potential energy, P.E. lost = The gain in kinetic energy, K.E.

58,369.5 J = 1/2×85.0×v²

v² = 58,369.5/(1/2*85.0) = 1373.4 m²/s²

v = 37.06 m/s

The skier will be going 52.41 - 37.06 = 15.35 m/s slower

The skier will be going 15.35 m/s slower

2) From the principle of conservation of energy, the amount of work done (energy used) = The (potential) energy gained by the load

The amount of work done by the electric hoist = 356,000 J

The mass of the load = 350.0 kg

The height to which the load is raised = h

The potential energy gained by the load = m×g×h = 350.0×9.81×h

356,000 J = 350.0×9.81×h

h = 356,000/(350.0*9.81) = 103.68 m

The height to which the load is lifted= 103.68 m

3) The initial potential energy of the roller coaster cart = 600*35.0*9.81 = 206010 J

The final potential energy = 600*28.0*9.81= 164808 J

The velocity at point 3  = 4.5 m/s

The kinetic energy at point 3 = 1/2*600*4.5^2 = 6075 J

The total energy at point 3 = 164808 + 6075 = 170,883 J

The energy loss = The initial potential energy at point 1 - Total energy at point 3

The energy loss = 206010 - 170,883 = 35,127 J

The heat energy due to friction that must have been produced between points 1 and 3 = 35,127 J

4) a. The heat energy absorbed = mass × specific heat capacity for water, [tex]C_{water}[/tex] × Temperature change

The mass of the water = 2.5×10² g = 0.25 kg

[tex]C_{water}[/tex] = 4,180 J/(kg·°C)

Initial temperature = 10.0°C

Final temperature = 95°C

The temperature change = 95.0°C - 10.0°C = 85.0°C

The heat energy absorbed = 0.25*4,180* 85 = 88,825 J = 88.825 kJ

(b) The percentage efficiency = (Heat absorbed/(Heat supplied)) × 100

The heat supplied = 543 kJ

The efficiency = (88.825/543) × 100  = 16.36 %

5) The mass of the box = 115 kg

Force acting on the rope = 255 N

The angle of inclination of the force to the horizontal = 24.5°

The distance the box is displaced = 15.0 m to the right

The work done = Force applied × distance moved in the direction of the force

The work done = Force applied × distance moved in the direction of the force

Given that the load moves a distance 15.0 m to the right,we have;

The component of the force acting in the direction of the movement of the load (to the right) is 225 × cos(24.5°) =  204.74 N

The work done = 204.7*15 = 3071.12 J

The amount of work done  = 3,071.12 J

Answer:

The answer is B.

Explanation:

Given that the current (Ampere) in a series circuit is same so we can ignore it. We can assume that the total voltage is 60V and all the 3 resistance are different, 20Ω, 40Ω and 60Ω. So first, we have to find the total resistance by adding :

Total resistance = 20Ω + 40Ω + 60Ω

= 120Ω

Next, we have to find out that 1Ω is equal to how many voltage by dividing :

120Ω = 60V

1Ω = 60V ÷ 120

1Ω = 0.5V

Lastly, we have to calculate the voltage at R1 so we have to multiply by 20 (R1) :

1Ω = 0.5V

20Ω = 0.5V × 20

20Ω = 10V

Explanation:

weight of the piano = mg

w = 99 x 10 =990 N

Answer:

3.5 kg

Explanation:

use the equation; (m1v1i) + (m2v2i) = (m1v1f) + (m2v2f)

= m1(0) - m1v1f = m2v2f - m2(0)

= (-2.0)(15)/-20

= 1.5 kg

then add the other piece (2.0kg)

1.5 + 2.0 = 3.5 kg

The mass of firework before explosion is 3.50kg.

mass flying to right  m1 = 2kg

                                v1  = 15 m/s

mass flying to left m2  = ?

                                v2 = - 20m/s

 initial velocity u = 0

by conservation of linear momentum

m1v1+ m2v2 = (m1+m2 ) u

2x 15- m2x 20 = 0

                 m2 = 1.50kg

therefore mass of firework before explosion

                   m1+m2

                     2+ 1.50

                  = 3.50kg

Mass is the amount of matter in a physical body. It  also measures the body's inertia, the resistance to acceleration when a net force is applied. The mass of an object also determines  its gravitational force on other objects. The basic SI  unit of mass is the kilogram.

Body mass is always constant. One way to calculate mass:

mass = volume × density. Weight is a measure of the gravitational force acting on a mass. The SI unit of mass is the "kilogram".

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Answer:

Net flux through the surface is zero.

Explanation:

Recall that the net electric flux through a closed surface depends on the net charge enclosed inside that surface.

In our case, there are two point charges of exactly opposite charge (net charge - zero), which are located inside the Gaussian surface of radius "2 a" centered at the origin - both charges are located at a distance "a" from the origin of coordinates, therefore inside the Gaussian surface.

Then the net flux through the surface is also ZERO.

Answer:

A.) Find the attached file

B.) 1.536 J

C.) 123N

Explanation:

Given that the force (F) in Newtons, of his breath as a function of the distance along the straw (x) in meters, can be modeled as a linearly decreasing function for the first half of the straw,

Half of the straw = 12.5 cm

Let Force F = dependent variable

And distance x = independent variable

A.) Find the attached file for the graph.

Sinnce the force decreases by half along the first half of the straw. Assume there is negligible friction and the straw is held horizontally

B.) Given that the mass M = 12g = 12/1000 = 0.012kg

And Velocity V = 16m/s

The workdone = the kinetic energy of the split ball

WD = 1/2mv^2

Substitutes m and V into the formula

WD = 1/2 × 0.012 × 16^2

WD = 1.536 Joule

C.) The maximum force acts on the spit ball will be at maximum kinetic energy.

Since work done = force × distance

Where distance = 12.5 cm

F × S = 1/2mv^2

Substitutes all the parameters

F × 0.0125 = 1.536

Make F the subject of formula

F = 1.536/0.0125

F = 122.88 N

The maximum force F0, that acts on the spitball is therefore equal to 123 N approximately.

We have that for the Question "(a) Sketch a plot of the force of his breath as a function of position along the straw, labeling the force at x = 0 as F0.

(b) If the spitball begins from rest and leaves the straw with a speed of 16 m/s, how much work is done on the spitball?

(c) What is the maximum force F0, that acts on the spitball?"

It can be said that

From the question we are told

mass of spitball = 12g through a 25.0 cm straw

Generally the equation for workdone is mathematically given as

[tex]= \frac{1}{2}mv^2 - 0\\\\= \frac{1}{2} * 12*10^{-3} * 16^2\\\\= 1.536J[/tex]

Maximum force

[tex]w = \frac{1}{2}*\frac{x_0}{2}*\frac{F_0}{2} + x_0*\frac{F_0}{2}\\\\w = \frac{5}{8}x_0F_0[/tex]

Therefore,

[tex]F_0 = \frac{8w}{5x_0}\\\\F_0 = \frac{8*1.536}{5*25*10^[-2]}\\\\F_0 = 6.4N[/tex]

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Answer:

F₂ = 21.97 N

Explanation:

this is a rotational equilibrium exercise, let's write the formula

         ∑ τ = 0

          F₁ d₁ - F₂ d₂ = 0

force F₁ is 17.5 N and its distance d₁ = 0.59m, the distance d₂ = 0.47m

          F₂ = F₁ d₁ / d₂

          F₂ = 17.5 0.59 / 0.47

          F₂ = 21.97 N

Answer:

1.92 kg of nitrogen.

Explanation:

The following data were obtained from the question:

Heat absorbed (Q) = 384000 J

Note: Heat of vaporisation (ΔHv) of nitrogen = 5600 J/mol

Next, we shall determine the number of mole of nitrogen that absorbed 384000 J.

This is illustrated below:

Q = mol·ΔHv

384000 = mole of N2 x 5600

Divide both side by 5600

Mole of N2 = 384000/5600

Mole of N2 = 68.57 moles

Next, we shall convert 68.57 moles of nitrogen, N2 to grams.

This can be obtained as follow:

Molar mass of N2 = 2 x 14 = 28 g/mol.

Mole of N2 = 68.57 moles.

Mass of N2 =..?

Mole = mass /molar mass

68.57 = mass of N2 /28

Cross multiply

Mass of N2 = 68.57 x 28

Mass of N2 = 1919.96 g

Finally, we shall convert 1919.96 g to kilograms.

This can be achieved as shown below:

1000g = 1 kg

Therefore,

1919.96 g = 1919.96/1000 = 1.92 kg.

Therefore, 1.92 kg of nitrogen were burned off.

Answer:

Explanation:

i cheat on Acellus cause I dont care about school. If i did I would be going to public school... Im never gonna use this info in my life so I dont bother learning it.

Answer:

D. transparent and translucent materials

Explanation:

OPAQUE MATERIALS:

Opaque Materials are those materials that absorb all the light and do not allow the light to pass through them.

TRANSLUCENT MATERIALS:

Translucent materials are those materials, that absorb a portion of light, allowing the light to partially pass through them.

TRANSPARENT MATERIALS:

Transparent materials are those materials that do not absorb the light and allow the light to completely pass through them.

Therefore, the correct option is:

D. transparent and translucent materials

Answer:

i) 20-30 kg

Explanation:

The child with the smallest mass range of 20-30 kg will require the smallest force to move his skate board because he/she has a smaller inertia force to overcome. The mass of a body is the measure of the inertia forces of the body. The inertia force makes it difficult for a body at rest to start moving, and a body already in motion to stop moving.

When the children try to move the skateboard, they exert a force that is proportional to the product of their mass and the acceleration with which they start moving. This force must exceed their body's inertia force before they would start moving.

from

F = ma

where F is the force required

m is the mass

a is the acceleration

We can see that for the given mass ranges, the children with the larger mass range will require more force in order to move their skateboard. Consequently, the child with the smallest mass range will require the smallest pushing force to move his skate board.

Answer:

The scientific questions here are:

a) How will climate change affect forests

b) How did life on Earth begin

c) Why did dinosaurs go extinct

Explanation:

Scientific question are logical quantifiable questions, whose answers can be measured. A good scientific question must have answers that can be tested by a carefully designed experiment or measurement. Some qualities like "prettiest" and "amazing" cannot be tested for nor are they measurable, and hence, they do not make a testable component of good scientific question.

Car at rest:

velocity= 0m/s

Acceleration:

0.2m/s²

Since total time:

3 min = 180s

Formula of acceleration:

acceleration = [final velocity - initial velocity] ÷ [total time]

Velocity at end:

0.2m/s² = [final velocity - 0m/s] ÷ [180s]

0.2m/s² × 180s = [final velocity]

[final velocity] = 36m/s

Distance travelled:

Velocity = displacement(distance) ÷ time

36m/s = displacement(distance) ÷ 180s

displacement(distance) = 36m/s × 180s

displacement(distance) = 6480m

Hey I'm sorry but i do not understand why the answer on your worksheet for distance travelled is 3240m... its half of what my answer is...

Answer: It has fewer decibels.

Explanation:

In a sound-wave, the intensity is defined as the power carried by the wave. The decibel is a measure of the ratio between two quantities. And in acoustics is used as the unit of the sound pressure level, which is related to the intensity of the wave, then:

As the intensity increases, we also should notice an increase in the decibels.

How is a less-intense wave different from a more-intense wave?

The less-intense wave has fewer decibels.

Answer:

It has fewer decibels.

Explanation:

Answer:

Length contraction

A moving object traveling at a velocity approaching the speed of light will appear to be shorter or to have undergone contraction.

The proportion by which the object is observed to have contracted is given by Lorentz transformation as follows;

[tex]L = L_{0}\cdot \sqrt{1 -\dfrac{v^{2}}{c^{2}}}= \dfrac{L_{0}}{\gamma }[/tex]

Time dilation

As the relative speed of motion of an object approaches the speed of light, the clock in the frame in motion will be observed to be moving slowly or dilated in a proportion given by Lorentz transformation as follows;

[tex]T = \dfrac{T_{0}}{\sqrt{1 -\dfrac{v^{2}}{c^{2}}}}[/tex]

Explanation:

Example of length contraction example

Two square boxes of side length L which are travelling at a velocity of 0.9 × c, are going to arranged in a single box of side side length  L according to length contraction Lorentz transformation, to  stationary observer we have

[tex]2 \times L\cdot \sqrt{1 -\dfrac{(0.9 \cdot c)^{2}}{c^{2}}}= 0.8 \cdot L[/tex]

To the stationary observer, the 2 boxes of length L will fit side by side in the single box of length L, while to those on the space ship carrying the boxes, the size of the single box is  [tex]L\cdot \sqrt{1 -\dfrac{(0.9 \cdot c)^{2}}{c^{2}}}= 0.4 \cdot L[/tex], which will not contain half of one box

Example of of time dilation example

Twin A of two twins, twin A and B went on a space journey at the speed of 0.87·c for 5 years, the number of years past for twin B when they meet again will be [tex]T = \dfrac{5}{\sqrt{1 -\dfrac{(0.87\cdot c)^{2}}{c^{2}}}} = 10.14 \ years[/tex]

Answer:

[tex]F_{net} = 1905 N[/tex]

[tex]\boxed{a = 7.62 m/s^2}[/tex]

Explanation:

For net force:

Firstly, finding the force of friction:

[tex]F_{k} =[/tex] [tex](micro)_{k} m g cos \theta[/tex]

Where [tex](micro)_{k}[/tex] is the coefficient of friction, m =  250 kg and g = 9.8 m/s²

[tex]F_{k} = (0.17)(25)(9.8) cos (52)\\F_{k} = (41.65)(0.616)\\F_{k} = 25.59 \ N[/tex]

Now, Finding of the pulling box:

[tex]F = mgsin\theta[/tex]

[tex]F = (250)(9.8) Sin (52)\\F = 2450 * 0.788\\F = 1930.6[/tex]

So, The net Force is

[tex]F _{net} = F - F_{k}[/tex]

[tex]F_{net} = 1930.6 -25.6\\[/tex]

[tex]F_{net} = 1905 N[/tex]

For Acceleration:

[tex]F_{net} = m a[/tex]

For a, it is:

=> [tex]a = \frac{F_{net}}{m}[/tex]

=> a = 1905 / 250

=> a = 7.62 m/s²

Answer:

A farmer with a field of solar panels.

Explanation:

The closest to a locally sources energy would have been

A coal mine located in their county.

But coal as an energy source is not environmentally friendly due to carbon emission, and should not be what the group should advocate for.

The best bet for them is

A farmer with a field of solar panels.

As solar panels are a source of green energy and green energy is what the environmental group should often and always advocate for

Answer:

W

Explanation:

The unit for Power which is  (Volt X Current) is Watts. and the symbol for Watts is W.