genes can be turned on or turned off not all genes are active at one time true or false

D.  

It increased deposition downstream.

Answer:

D. It increased deposition downstream.

Explanation:

Tailing is the material leftover after separation of valuable material from ore. Tailing ponds are made near moving water are not good for water as they increase water pollution. In case of waste rocks from mine dumped near water body such as river, may reduce the depth of river bed and increase chances of flood. These deposits also increase deposition downstream and form big deltas.

The 'slope' of the road is (rise between two points) / (hotizontal distance between the same two points).  Or (rise)/(run).  It's also the tangent of the angle between the horizontal and the incline.

In this problem, your 'run' is 2.4 km, and the 'rise' is 160 m.

The slope of the incline is (160) / (2,400) .

That's 0.0667 .

To answer the question, you need to find the ANGLE whose tangent is that same number.

If your calculator has ANY functions on it, then " tan⁻¹ " is the one you want.  Key in a number, and " tan⁻¹ " will give you the angle whose tangent is that number.

The angle of the road above the horizontal is found using trigonometry, specifically the tangent function, which is the ratio of the elevation gain to the distance traveled along the road. By applying the arctan function to 160m/2400m, we can calculate the angle of inclination in degrees.

The question involves finding the angle of the road above the horizontal when the elevation change and the distance traveled along the road are known. This requires the use of trigonometry to determine the angle, given the rise (elevation change) and run (distance traveled along the road).

To find the angle, we can use the tangent function, which is the ratio of the opposite side to the adjacent side in a right triangle. In this scenario, the rise is 160 m and the run is 2400 m (2.4 km). We need to convert the run into meters to match the units of the rise, making the run 2400 m.

Now we compute the angle θ:

Once we calculate the arctan(1/15), we will get the angle of inclination of the road in degrees.

Answer:

the elements towards the bottom left corner

Explanation:

Metals are the substances which tend to lose their valence electrons in order to attain stability.

For example, metals of group 1 are lithium, sodium, potassium, rubidium and cesium.

And, each of these elements have only 1 valence electron present. So, it is much easier to lose just one electron rather than losing 2 or 3 valence electrons.

Hence, alkali metals are the most reactive substances of the periodic table and they are present at extreme left side of periodic table.

Therefore, we can conclude that the most reactive metals are located at the extreme left of the periodic table.

C is the correct option

As momentum = (mass) (velocity)

P=mv

So the object having greater mass has less velocity and the object having smaller mass will move faster. But product of mass and velocity is same to each other.

Let the salmon jump with speed v at an angle of 33.3 degree

So here we can find out the components of his velocity in x and y direction

[tex]v_x = v cos33.2[/tex]

[tex]v_y = v sin33.2[/tex]

now the horizontal displacement of the salmon is 3.15 m so he cover this horizontal distance with constant speed as there is no acceleration in x direction

here we can say

[tex]v_x * t = 3.15[/tex]

[tex]v cos33.2 * t = 3.15[/tex]

[tex]v*t = 3.76[/tex]

now in Y direction it is an accelerated motion as it is accelerated due to gravity

[tex]y = v_y * t + \frac{1}{2}at^2[/tex]

[tex]-0.45 = v sin33.2* t - \frac{1}{2}*9.8* t^2[/tex]

now we will plug in v*t = 3.76

[tex]-0.45 = 3.76 * sin33.2 - 4.9 * t^2[/tex]

[tex]4.9 t^2 = 2.51[/tex]

[tex]t^2 = 0.512[/tex]

[tex]t = 0.72 s[/tex]

now speed v is given by equation above

[tex]v*t = 3.76[/tex]

[tex]v*0.72 = 3.76[/tex]

[tex]v = 5.25 m/s[/tex]

so here he must have to jump with minimum speed of 5.25 m/s

Let the salmon jump with speed v at an angle of 33.3 degree

So here we can find out the components of his velocity in x and y direction

[tex]v_x = v cos33.2[/tex]

[tex]v_y = v sin33.2[/tex]

now the horizontal displacement of the salmon is 3.15 m so he cover this horizontal distance with constant speed as there is no acceleration in x direction

here we can say

[tex]v_x * t = 3.15[/tex]

[tex]v cos33.2 * t = 3.15[/tex]

[tex]v*t = 3.76[/tex]

now in Y direction it is an accelerated motion as it is accelerated due to gravity

[tex]y = v_y * t + \frac{1}{2}at^2[/tex]

[tex]-0.45 = v sin33.2* t - \frac{1}{2}*9.8* t^2[/tex]

now we will plug in v*t = 3.76

[tex]-0.45 = 3.76 * sin33.2 - 4.9 * t^2[/tex]

[tex]4.9 t^2 = 2.51[/tex]

[tex]t^2 = 0.512[/tex]

[tex]t = 0.72 s[/tex]

now speed v is given by equation above

[tex]v*t = 3.76[/tex]

[tex]v*0.72 = 3.76[/tex]

[tex]v = 5.25 m/s[/tex]

so here he must have to jump with minimum speed of 5.25 m/s

efficiency of the heat engine is calculated by the formula

[tex]\eta = 1- \frac{T_c}{T_h}[/tex]

here we know that

[tex]T_c [/tex] = cold temperature

[tex]T_h [/tex] = hot temperature

now we will find the efficiency of all

1) for W

[tex]\eta_1 = 1- \frac{T_c}{T_h}[/tex]

[tex]\eta_1 = 1- \frac{120}{620}[/tex]

[tex]\eta_1 = 0.806[/tex]

2) for X

[tex]\eta_2 = 1- \frac{T_c}{T_h}[/tex]

[tex]\eta_2 = 1- \frac{100}{840}[/tex]

[tex]\eta_2 = 0.88[/tex]

3) For Y

[tex]\eta_3 = 1- \frac{T_c}{T_h}[/tex]

[tex]\eta_3 = 1- \frac{300}{900}[/tex]

[tex]\eta_2 = 0.67[/tex]

4) for Z

[tex]\eta_4 = 1- \frac{T_c}{T_h}[/tex]

[tex]\eta_4 = 1- \frac{25}{500}[/tex]

[tex]\eta_4 = 0.95[/tex]

So here most efficient engine is Z and least is Y

so we can arrange it as

Z > X > W > Y

so 3rd option is correct here

Answer:

C.) Z, X,W, Y

Scientific law is also known as natural law. It  imply a cause and effect between the observed elements and always apply under the same conditions .

Scientific law is a statement based on repeated experimental observations that describes some aspect of the Universe.

B. Scientific theories attempt to explain why natural events occur.

Answer: B. Scientific theories attempt to explain why natural events occur.

Explanation:

The scientific theories are the detailed explanations which gives reasons for the cause of natural events, processes and phenomena that occur in the natural world. These are supported by the evidences and observations that are obtained through experimental trials. These theories can be changed due to the changing of facts due to further experimental studies conducted by new generation scientists.

When an electron is accelerated through potential difference then the speed that it attain will be explained by energy conservation

here by energy conservation we can say that

change in kinetic energy of electron = electrostatic potential energy gained through given potential difference

kinetic energy is given as

[tex]KE = \frac{1}{2}mv^2[/tex]

electrostatic potential energy is given as

[tex]PE = qV[/tex]

now by energy conservation

[tex]qV = \frac{1}{2}mv^2[/tex]

given that for electron

[tex]m = 9.1 * 10^{-31} kg[/tex]

[tex]v = 3 * 10^7 m/s[/tex]

[tex]q = 1.6 * 10^{-19} C[/tex]

now by plug in values

[tex]1.6 * 10^{-19} * V = \frac{1}{2}*9.1* 10^{-31} *(3*10^7)^2[/tex]

[tex]V = \frac{4.095 * 10^{-16}}{1.6 * 10^{-19}}[/tex]

[tex]V = 2559.4 Volts[/tex]

So here it is accelerated through potential difference of 2559.4 Volts

The electric potential is 4100 V or 4.1kV.

We know that the kinetic energy of the moving electron is equal to the 1/2mv^2. On this basis, we can write;

1/2mv^2 = eV

Where;

m = mass of the electron

v = speed of the electron

V = potential of the electron

e = charge on the electron.

Hence;

V = 1/2mv^2 /e

V = 0.5 × 9.11 × 10^-31 × (3 × 10^7)^2/1.6 ×10^-19

V = 4100 V or 4.1kV

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I would say B because not wearing a seatbelt is an example of risky behavior, which they’re were trying to prevent

• Objects “fall” toward the center of Earth.  (TRUE)

Since the gravitational force between earth and any object is always along the line joining the centers of two so all the objects near the surface of earth will always feel force towards the centre of the earth due to gravity.

• Objects are pulled by Earth but do not pull on Earth.  (FALSE)

Since gravitational force will always follow Newton's III law as per which every action has equal and opposite reaction force so object near the surface of earth will also pull the earth as earth is pulling the object towards the center.

• Objects accelerate at a rate of 9.8 m/s each second.  (TRUE)

Since acceleration due to gravity of Earth is 9.8 m/s^2 so here we can say that all objects near the surface of earth will accelerate towards the center of earth at rate of 9.8 m/s^2 due to gravitational pull.

• Objects travel at a rate of 9.8 m/s to are the center of Earth. (FALSE)

Since earth is pulling all objects near its surface with gravitational force so objects can not move at constant speed but it will move with constant acceleration.

• Objects are pulled by Earth more strongly than they pull on Earth. (FALSE)

Since gravitational force will always follow Newton's III law which say every action has equal and opposite reaction so we can say that force due to all objects on earth will be same as the force of earth on the object.

Answer: A sealed calorimeter is a closed system because thermal energy is not transferred to the environment.

A closed system is an isolated system where there is no transfer of energy with its surroundings. Also the system is not subjected to any external force whose source is external to the system.

Answer:C. Because thermal energy has not transferred to the environment.

Explanation:

Forces are presented as straight arrows pointing in the direction they function  on the body.

The force arrows always points straight arrows.

ANSWER:

Abseiling rope is tested beyond twice the maximum possible weight when in use because of safety purposes.

EXPLANATION:

Every rope has its elastic limit.Abseiling rope is used basically for climbing or descending purposes so this type of rope must be of quite good quality and  it must bear maximum possible weight. We test it  just to check the elastic limit of the rope so that the rope shouldnot increase its elastic limit and it doesnot break when we use it.

Mass of the sound reflector is given as

[tex]m_1 = 170 kg[/tex]

mass of the chain itself is

[tex]m_2 = 8 kg[/tex]

now here since this system is suspended at rest and no acceleration is given for the system so in order to find the tension in the chain we will just use force balance equation

As per force balance we can say that weight of the chain and reflector downwards will be counter balanced by tension in the string

Now here we will have

[tex]T = m_1g + m_2g[/tex]

since chain is given with some mass so tension at the top end of the chain will be

[tex]T = 170* 9.8 + 8 * 9.8[/tex]

[tex]T = 1744.4 N[/tex]

So here tension in the chain will be 1744.4 N at the top end and this tension will decrease as we move down along the length of the chain.

Answer

224 Km

4 Km

Explanation

Part 1

The plane flies 100 Km north and then 200 Km east. This makes a 90° turn. To get the distance taken by the plane we get the hypotenuse.

c² = a² + b²

c² = 100² + 200²

   = 50,000

c = √50,000

    = 223.606 Km

The answer to the nearest whole number is 224 Km

Part 2

If the runner run 15 Km north then 11 Km south, the resultant distance would be,

15 - 11 = 4 Km

I’m not sure but I’m guessing wind.

Answer:

wind

Explanation:

From powering ships and windmills to wind-farms that generate electricity, wind has proven to be somewhat useful.

Answer:

Energy in KWH  = Power in KW * Time in hours

Cost  is # of KWH  * the cost per KWH

                      350 kwh

Explanation:

The monthly cost of using a 700-W refrigerator that runs for 10 h a day if the cost per kWh is $0.20 is $42.

The cost price per watt is the amount of money required to use one watt or kilo watt electricity,

To find the total cost of electricity used, multiply the cost price of electricity per watt to total watts of electricity used.

Given information-

The power used by the refrigerator is 700- W per hour.

Total run time of the refrigerator is 10 hours per day.

The cost of the electricity is $0.20 kWh.

As, the power used by the refrigerator is 700- W per hour and total run time of the refrigerator is 10 hours per day. The power used by the refrigerator per day is,

[tex]P=700\times10\\P=7000\rm Wh\\P=7\rm kWh[/tex]

There is total 30 days in a month. Thus the total  power used by the refrigerator per month is,

[tex]P=7\times30\\P=210\rm kWh[/tex]

As the cost of the electricity is $0.20 kWh. Thus the cost of 210 kWh electricity is,

[tex]C=0.2\times210\\C=42[/tex]

Thus the monthly cost of using a 700-W refrigerator that runs for 10 h a day if the cost per kWh is $0.20 is $42.

Learn more about the cost price per watt here;

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Here it is an application of Newton's III law

as we know by Newton's III law that every action has equal and opposite reaction

So here as we know that two boys jumps off the boat with different forces

from front side of the boat the boy jumps off with force 45 N which means as per Newton's III law if boy has a force of 45 N in forward direction then he must apply a reaction force on the boat in reverse direction of same magnitude

So boat must have an opposite force on front end with magnitude 45 N

Now similar way we can say

from back side of the boat the boy jumps off with force 60 N which means as per Newton's III law if boy has a force of 60 N in backward direction then he must apply a reaction force on the boat in reverse direction of same magnitude

So boat must have an opposite force on front end with magnitude 60 N

So here net force due to both jump on the boat is given by

[tex]F_{net} = F_1 - F_2[/tex]

[tex]F_{net} = 60 - 45[/tex]

[tex]F_{net} = 15 N[/tex]

so boat will have net force F = 15 N in forward direction due to both jumps

answer is C. dressing to protect hands

C. a windy and powerful storm system

C. a windy and powerful storm system

The answer is D) 4,3,2

Just had this question

Here object is dropped from height "h"

so we can say its initial speed is zero

and it will accelerate downwards due to gravity

now we can say it will take time T to hit the ground

now we can use

[tex]h = v_i*t + \frac{1}{2}gt^2[/tex]

[tex]h = 0 + \frac{1}{2}*gT^2[/tex]

now it is given that it will take 1 second to drop h/2 height to strike the ground

so here we have can say that in "T - 1" s it will cover the h/2 distance from start

[tex]h/2 = 0 + \frac{1}{2}g(T-1)^2[/tex]

now we can say

[tex]h = g(T-1)^2[/tex]

from above two equations we have

[tex]\frac{1}{2}gT^2 = g(T-1)^2[/tex]

[tex]T^2 = 2(T^2 + 1 -2T)[/tex]

[tex]T^2 - 4T + 2 = 0[/tex]

[tex]T = 3.41 s[/tex]

now we can find total height of the drop by first equation

[tex]h = \frac{1}{2}gT^2[/tex]

[tex]h = \frac{1}{2}*9.81*3.41^2[/tex]

[tex]h = 57.2 m[/tex]

Answer:

Explanation:

The epithelial tissues cover the body surfaces, forms a lining over the body cavities and hollow organs. These tissues also forms a protective barrier between the external environment and the body.

The epithelial tissues are the tissues which performs various functions. These tissues are composed of cells that are laid close to each other with the cells that lies in the close association with each other. The structure and function of the epithelial cells vary from both upper and lower surfaces. Due to variety in the functions of the epithelial tissues like protection, secretion, cellular transportation, filtration, selective absorption and sensing, these are called as the versatile tissues.

We are standing still inside an elevator

So our speed in the frame of elevator is zero

we can write this relative speed as

[tex]v_{pE} = v_p - v_E[/tex]

also we know that speed of the elevator is 55 mph

[tex]v_E = 55 mph[/tex]

now the velocity in relative frame is zero as he is  still in the moving elevator while in the ground frame or observing from the ground its velocity will be same as velocity of elevator.

So whenever an object is at rest in a moving frame then its relative velocity with respect to that frame must be ZERO

The use of force to move an object is defined as 'work' in physics. Work is done when a force moves an object. The amount of work is measured as force multiplied by distance.

The use of force to move an object is called work. This is a fundamental concept in Physics, specifically in the field of mechanics. According to this principle, work is done when a force that is applied to an object moves that object. For instance, when you push a box and it moves, you're doing work on the box. The amount of work done is calculated by multiplying the force by the distance over which it is applied (Work = Force x Distance). If there is no movement despite the force applied, no work is done according to physics.

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Planets move in elliptical orbits and this theory was formulated by Johannes Kepler.  Kepler's laws of planetary motion defined a set of rules followed by the planets while revolve around the sun and determines their orbits.  

This modified the earlier theory of circular orbits from Nicholas Copernicus.

Kepler made two key modifications to Copernicus's model:

1. Kepler modified the circular orbits of planets proposed by Copernicus into elliptical orbits.

2. Kepler introduced the concept of varying planetary speeds along their orbits, rather than assuming constant speeds as Copernicus did.

To calculate the modifications Kepler made:

1. Elliptical Orbits:

  - Kepler's first law states that planets move in elliptical orbits with the Sun at one of the foci. The formula for an ellipse is [tex]\( \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \)[/tex], where [tex]\( a \)[/tex] is the semi-major axis and [tex]\( b \)[/tex] is the semi-minor axis.

  - In contrast, Copernicus's model assumed perfect circular orbits with the Sun at the center.

2. Varying Planetary Speeds:

  - Kepler's second law states that a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time. Mathematically, this is expressed as [tex]\( \frac{dA}{dt} = \text{constant} \),[/tex]where [tex]\( A \)[/tex] is the area swept and [tex]\( t \)[/tex] is time.

  - Copernicus's model assumed uniform orbital speeds for planets.

Kepler's modifications were revolutionary as they better explained observations such as varying planetary brightness and retrograde motion. These changes laid the foundation for modern celestial mechanics and our understanding of planetary motion.

Complete Question:

What modifications did Kepler make to Copernicus model?

Latent heat is related to changes in phase between liquids ,gases and solids.

Sensible heat is related to changes in temperature of a gas or object with no change in phase.