Tarnishing of iron is similar to which of the following changes?
O Folding a paper
O Shredding a paper
Burning a paper
Dropping a paper

Answer:

C: the process by which stars create the heavier elements

Explanation:

Stellar nucleosynthesis is defined as the process of nuclear fusion by which heavier elements are formed within stars by from the combination of protons and neutrons gotten from the nuclei of lighter elements.

Looking at the options, the correct one is Option C

Answer:

i) a₁ = -g (sin θ + μ cos θ), x = v₀² / 2a₁

ii) W = mg L sin  θ ,  iii)     Wₙ = 0

iv)  W = - μ m g  L cos  θ x

Explanation:

With a drawing this exercise would be clearer, I understand that you have a block on a ramp and it is subjected to some force that makes it rise, for example the tension created by a descending block.

The movement is that when the system is released, the tension forces are greater than the friction and the component of the weight and therefore the block rises up the ramp

At some point the tension must become zero, when the hanging block reaches the ground, as the block has a velocity it rises with a negative acceleration to a point and stops where the friction force and the weight component would be in equilibrium along the way. along the plane

i) Let's use Newton's second law

the reference system is with the x axis parallel to the ramp

Axis y

      N - W cos θ = 0

X axis

      T - W sin θ - fr = ma

the friction force is

      fr = μ N

      fr = μ mg cos θ

we substitute

      T - m g sin sin θ - μ mg cos θ = m a

      a = T / m - g (sin θ + μ cos θ)

With this acceleration we can find the height that the block reaches, this implies that at some point the tension becomes zero, possibly when a hanging block reaches the floor.

      T = 0

       a₁ = -g (sin θ + μ cos θ)

       v² = v₀² - 2a1 x

       v = 0       at the highest point

       x = v₀² / 2a₁

ii) the work of the gravitational force is

       W = F .d

       W = mg sin  θ   L

iii) the work of the normal force

the force has 90º with respect to the displacement so cos 90 = 0

         Wₙ = 0

iv) friction force work

friction force always opposes displacement

         W = - fr d

         W = - μ m g cos  θ L

Answer:

(a) 3.93 m/s

(b) 861.66 m

Explanation:

A = 4.5 m/s  [27° S of W] for 3.0 minutes

B = 3.5 m/s [35° S of E] for 4.1 minutes

Distance A = 4.5 x 3 x 60 = 810  m

Distance B = 3.5 x 4.1 x 60 = 861 m

(a) The average speed is defined as the ratio of the total distance to the total time.

Total distance, d = 810 + 861 = 1671 m

total time, t = 3 + 4.1 = 7.1 minutes = 7.1 x 60 = 426 seconds

The average speed is

[tex]v=\frac{1671}{426}=3.93 m/s[/tex]

(b)

[tex]\overrightarrow{A} = 810(- cos 27 \widehat{i} - sin 27 \widehat{j})=- 721.7 \widehat{i} - 367.7 \widehat{j}\\\\\overrightarrow{B} = 861( cos 35 \widehat{i} - sin 35 \widehat{j})= 705.3 \widehat{i} - 493.8 \widehat{j}\\\\\overrightarrow{C} = (- 721.7 + 705.3) \widehat{i} - (367.7 + 493.8) \widehat{j} \\\\\overrightarrow{C}= - 16.4 \widehat{i} - 861.5 \widehat{j}[/tex]

The magnitude is

[tex]C =\sqrt{16.4^2+861.5^2} = 861.66 m[/tex]

Answer:

Heavier than 2.2 pounds

Explanation:

Answer: The uses of static electricity include:

--> photocopying machines

--> precipitators

The dangers of static electricity include:

--> sparks that can lead to explosion

--> Damage to electronic equipment

Explanation:

STATIC electricity is defined as the imbalance that exists between a positive and a negative charge either within or outside an object. This is because all physical objects are made up of atoms which contains protons, electrons and neutrons. The protons are positively charged, the electrons are negatively charged, and the neutrons are neutral. This shows that physical objects are made up of charges.

Opposite charges attract each other (negative to positive). Like charges repel each other (positive to positive or negative to negative). Most of the time positive and negative charges are BALANCED in an object, which makes that object neutral.

Applications( uses) of static electricity include:

--> photocopying machines: Inkjet photocopiers and printers use static electricity to guide a minute jet of ink to the page’s precise position.

--> precipitators: the static electricity is applied in an electrostatic precipitator whereby they remove smoke from waste gases before they pass out of the chimneys in power stations that burn fossil fuels.

The disadvantages (dangers) of static electricity include:

--> Sparks that can lead to explosion: sparks generated from static electricity can cause fires or explosions due to the ignition of flammable or explosive mixtures.

--> Damage to electronic equipment: this is due to components from electrostatic discharge.

Answer:

20 m/ s

Explanation:

change in velocity = 4m/ s

[tex]acceleration = \frac{rate \: of \: change \: of \: velocity}{time} [/tex]

[tex]acc = \frac{4}{2} \\ = 2[/tex]

initial velocity = 0m/ s

[tex]2 = \frac{v - 0}{10} [/tex]

cross multiplying

[tex]20 = v[/tex]

so the velocity after 10s will be 20m/s

Answer:

I = sum m *r^2    where m represents the (small) individual masses and r is the distance of that mass from center of rotation

Note:  sum m = M

For the hoop given all masses are at a distance RRR from the center of rotation

I = MMM * RRR^2

Answer:

theory

Explanation:

took the quiz

Answer:

displacement

Explanation:

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

A reference point refers to a location or physical object from which the motion (movement) of another physical object or body can be determined.

Mathematically, the motion of an object is described in terms of acceleration, time, distance, speed, velocity, position, displacement, etc.

Displacement can be defined as the change in the position of a body or an object. It is a vector quantity because it has both magnitude and direction.

This ultimately implies that, the difference between the starting and ending positions of a physical object is generally referred to as displacement

Answer:

Jo

Explanation:

irradiating food doesn't make it radioactive (that's contamination) and beta particles are stopped by aluminium foil or thin metals, so it may not pass through thick packaging (usually gamma is used to irradiate foods as it can pass through the packaging)

Answer:

F2 = 900 lbs

Explanation:

From pascal principle;

F1/A1 = F2/A2

Force on cylinder at left; F1 = 100 lbs

Diameter of cylinder at left; d1 = 2 inches

Diameter of cylinder at right; d2 = 6 inches

Formula for area of top of cylinder = πr²

Thus;

Area of top of left cylinder; A = π × 2² = 4π

Area of top of right cylinder; A = π × 6² = 36π

Thus;

100/4π = F2/36π

F2 = (36π × 100)/4π

F2 = 900 lbs

Answer:

Coulomb, unit of electric charge in the metre- kilogram- second- ampere system, the basis of SI system of physics unit. The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.

Answer:

10 pa

Explanation:

4kg* 10 (or 9.8m/s2) = 40

40N /4m2 =10

Answer:

Explanation:

This is a simple gravitational force problem using the equation:

[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] where F is the gravitational force, G is the universal gravitational constant, the m's are the masses of the2 objects, and r is the distance between the centers of the masses. I am going to state G to 3 sig fig's so that is the number of sig fig's we will have in our answer. If we are solving for the gravitational force, we can fill in everything else where it goes. Keep in mind that I am NOT rounding until the very end, even when I show some simplification before the final answer.

Filling in:

[tex]F_g=\frac{(6.67*19^{-11})(7.2000*10^{26})(5.0000*10^{23})}{(6.10*10^{11})^2}[/tex] I'm going to do the math on the top and then on the bottom and divide at the end.

[tex]F_g=\frac{2.4012*10^{40}}{3.721*10^{23}}[/tex] and now when I divide I will express my answer to the correct number of sig dig's:

[tex]Fg=[/tex] 6.45 × 10¹⁶ N

Answer:

(a) The motion is uniform

(b)  11.11 m/s

Explanation:

(a)

From the table below, the motion of the bus is uniform.

(b)

Speed(s) = Δd/Δt

s = Δd/Δt............. Equation 1

From the table,

Given: Δd = 10 km = 10000 m, Δt = 15 minutes = (15×60) = 900 seconds

Substitute these values into equation 1

s = 10000/900

s = 11.11 m/s

Explanation:

when the distance between the 2 objects is halved, the gravitational force between the 2 objects is doubled. when the distance between the 2 objects is doubled then the gravitational force doubles.

Answer:

The time in which the pendulum does a complete revolution is called the period of the pendulum.

Remember that the period of a pendulum is written as:

T = 2*pi*√(L/g)

where:

L = length of the pendulum

pi = 3.14

g = 9.8 m/s^2

Here we know that  L = 14.4m

Then the period of the pendulum will be:

T = 2*3.14*√(14.4m/9.8m/s^2) = 7.61s

So one complete oscillation takes 7.61 seconds.

We know that the pendulum starts moving at 8:00 am

We want to know 12:00 noon, which is four hours after the pendulum starts moving.

So, we want to know how many complete oscillations happen in a timelapse of 4 hours.

Each oscillation takes 7.61 seconds.

The total number of oscillations will be the quotient between the total time (4 hours) and the period.

First we need to write both of these in the same units, we know that 1 hour = 3600 seconds

then:

4 hours = 4*(3600 seconds) = 14,400 s

The total number of oscillations in that time frame is:

N = 14,400s/7.61s = 1,892.25

Rounding to the next whole number, we have:

N = 1,892

The pendulum does 1,892 oscillations between 8:00 am and 12:00 noon.

Answer:

. The SI unit of volume is the cubic meter (m3), which is a derived unit.

Liter (L) is a special name for the cubic decimeter (dm3).

Answer:

1000.

Explanation:

Thousand more steps could be taken when the number of cells was  increased from 3 to 5 because in the data, the number of cells i.e. 5 was achieved on 1000 steps. According to the data, the number of cells i.e. 1 was achieved on 800 steps, the number of cells i.e. 5 was achieved on 1000 steps, the number of cells i.e. 2 was achieved on 600 steps, the number of cells i.e. 3 was achieved on 400 steps and the number of cells i.e. 4 was achieved on 200 steps. So we can say that 1000 steps are needed for the number of cells increased from 3 to 5.

Answer:

25 kg

Explanation:

Given,

Acceleration ( a ) = 2 m/s^2

Force ( F ) = 50 N

To find : Mass ( m ) = ?

Formula : -

F = ma

m = F / a

= 50 / 2

m = 25 kg

So, the mass of the body is 25 kg.

Answer:

dependent: the outcome of the experience

independent variable: everything literaly.

Independent is where you change some variables and see the result

Dependent is literaly the result, or the outcome dependent on the exprience.

Explanation:

I got u.

Answer:

Explanation:

Newton's law of gravitation states that every particle of matter attracts any other particle in the universe with a force directly proportional to the product of there masses and inversely proportional to the square of the distance between them.

This law is also called universal law because it is applicable to all masses at all distances irrespective of the medium.

Answer:

We know that for a pendulum of length L, the period  (time for a complete swing) is defined as:

T = 2*pi*√(L/g)

where:

pi = 3.14

L = length of the pendulum

g = gravitational acceleration = 9.8 m/s^2

Now, we can think on the swing as a pendulum, where the child is the mass of the pendulum.

Then the period is independent of:

The mass of the child

The initial angle

Where the restriction of not swing to high is because this model works for small angles, and when the swing is to high the problem becomes more complex.

Answer:

both answer is option C

Explanation:

tag me brainliest

Explanation:

Hey there!

Given;

Mass of one object (m1) = 250kg

Mass of another object (m2) = 400 kg

Distance (d) = 100 m

Gravitational constant (g) = 6.67*10^-11

Now;

[tex]f = \frac{g.m1.m2}{ {d}^{2} } [/tex]

Keep all values;

[tex]f = \frac{6.67 \times {10}^{ - 11} \times 250 \times 400}{ {(100)}^{2} } [/tex]

Simplify

[tex]f = \frac{6.67 \times {10}^{ - 11} {10}^{5} }{10000} [/tex]

[tex]f = \frac{6.67 \times {10}^{ - 6} }{10000} [/tex]

Therefore, gravitational force is 6.67*10^-10.

Hope it helps!

Answer:

Explanation:

The dart will go forward horizontally with velocity of 19 m/s. It will also fall downwards with initial velocity of zero and gravitational acceleration of 9.8 m/s².

Distance PQ covered by the dart can be calculated using the following formula.

s = ut + 1/2 at²

u is initial velocity , a is acceleration and t is time.

Putting the values

s = 0 + 1/2 x 9.8 x .19²

= .1769 m

= 17.69 cm.

Answer:

the statement is TRUE

Explanation:

Most lenses are made of glass that has a strong absorption below 400 nm,

Only special evaporation lenses are made of quartz and fused silica which has a high absorption below 200 nm.

therefore the statement is TRUE

Answer:

 v_f = 24.3 m / s

Explanation:

A) In this exercise there is no friction so energy is conserved.

Starting point. On the roof of the building

         Em₀ = K + U = ½ m v₀² + m g y₀

Final point. On the floor

         Em_f = K = ½ m v_f²

         Emo = Em_g

         ½ m v₀² + m g y₀ = ½ m v_f²

        v_f² = v₀² + 2 g y₀

let's calculate

        v_f = √(10² + 2 9.8 25)

        v_f = 24.3 m / s

Answer:

The force of gravitational attraction between them also decreas