The Periodic Table Question 3 of 10 Based on the trend in valence electrons across periods for main-group elements, how many valence electrons does fluorine (F) have? O A. 4 B. 7 O C. 6 D. 5 SUBT​

Answer:

These atomos are called isotopes.

Explanation:

Each chemical element is characterized by the number of protons in its nucleus, which is called the atomic number (Z).

The number of neutrons in the nucleus can vary. There are almost always as many or more neutrons than protons. The atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus.

The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element. That is, isotopes are atoms whose atomic nuclei have the same number of protons but different numbers of neutrons.

So, these atomos are called isotopes.

Answer: B

"Ball 1 at 0.21 m/s left, Ball 2 at 0.22 m/s left"

Answer:

30,000kgm/s

Explanation:

Change in momentum is expressed as;

Change in momentum = mass × change in velocity

∆M = m∆v

Mass m = 1.5×10³kg = 1500kg

∆v = 30-10 =20m/s

Substitute into the formula

Change in momentum = 1500(20)

Change in momentum = 30,000kgm/s

Answer:

The horizontal distance traveled by the skydiver is 510.8 m.

Explanation:

Given;

height of fall, h = 800 m

initial velocity of the airplane, u = 40 m/s

The time to fall to the ground is calculated as;

[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2 \times 800}{9.81} }\\\\t = 12.77 \ s[/tex]

The horizontal distance or range of the motion is calculated as;

R = ut

R = 40 m/s x 12.77 s

R = 510.8 m

Therefore, the horizontal distance traveled by the skydiver is 510.8 m.

Answer:

Answer:

The last option.

Explanation:

Since you are going down, the gravitational potential energy would go down too. Thus, the gravitational potential energy decreases.

Since the gravitational potential energy is converted to kinetic energy when you move down, there is an increase in kinetic energy.

Answer:

The fourth option

Explanation:

Answer:

b

Explanation:

Complete question:

A train has an initial velocity of 44m/s and an acceleration of -4m/s². calculate its velocity​ after 10s ?

Answer:

the final velocity of the train is 4 m/s.

Explanation:

Given;

initial velocity of the train, u = 44 m/s

acceleration of the train, a = -4m/s² (the negative sign shows that the train is decelerating)

time of motion, t = 10 s

let the final velocity of the train = v

The final velocity of the train is calculated using the following kinematic equation;

v = u + at

v = 44 + (-4 x 10)

v = 44 - 40

v = 4 m/s

Therefore, the final velocity of the train is 4 m/s.

Answer:

gases.

Explanation:

gases have the highest volume. if you compress (increase pressure) a gas, the volume decreases and it will take up less space as a liquid, and if you compress more, the liquid will become a solid.

additionally info: this is generally true, but as you get into more difficult subjects, this rule does not hold. for example, some substances cannot obtain a certain phase of matter when they are a certain temperature and or pressure. but that could be way more out of this questions league.

Answer:

Answers below--

Explanation:

1. F/Force

2.H/Contact force

3.A/Non-contact force

4.C/electric force

5.D/gravity

6.I(i)/magnetic force

7.J/kilogram

8.G/newton

9.B/friction

10.E/lubricant

Answer:

Gravity controls the movement of the planets around the sun, holds together stars grouped in galaxies, and galaxies grouped in clusters.  The Universal Law of Gravitation depends on two things.  First it depends on mass of each object  and the second factor is the distance between two objects.  If the mass of one object is Larger, the gravitational pull towards it will be larger  and the smaller distance, the larger the gravitational pull will be between the objects. Therefore the Larger planets have more moon and the inner planets have less.

Explanation:

Answer:

2.97 meters

9.85 m/s^2

Explanation:

Given that :

Period (T1) = 3.45 seconds

When length , l is shortened by 1m, period (T2) = 2.81 seconds

Using the relation :

T = 2π√l/g

g = acceleration due to gravity

T1 = 2π√L/g - - - - (1)

Period 2:

x = shortened length = 1m

T2 = 2π√L-x/g - - - (2)

Square both sides

T1² = (2π)² L/g - - - (3)

T2² = (2π)² L-x/g - - (4)

Divide 3 and 4

(T2/T1)² = (L-x) / L

(2.81/3.45)^2 = (L - 1) / L

0.6633984 = (L - 1) / L

0.6633984L = L - 1

0.6633984L - L = - 1

−0.336601L = - 1

L = 1 / 0.336601

L = 2.9708764

Length = 2.97 meters

Acceleration due to gravity :

g = L(2π/T1)^2

g = 2.97(2π / 3.45)^2

g = 2.97 * 3.3168172

g = 9.8509

g = 9.85 m/s^2

g

Answer:

B. 90km/hr

Explanation:

The formula for finding velocity =

Displacement/time

The displacement of the car has been given to be = 1215 km West

Time it took to go from Dallas to Paso = 13.5 hours

Then velocity = 1215/13.5

= 90

Therefore velocity = 90km/hour

Option B is the correct answer to this question.

Thank you!

Answer:

1m/s²

Explanation:

Given parameters:

Initial velocity  = 2m/s

Final velocity  = 4m/s

Time of chase  = 2s

Unknown:

Acceleration = ?

Solution:

Acceleration is the rate of change of velocity with time;

 A = [tex]\frac{v - u }{t}[/tex]  

A is the acceleration

v is the final velocity

u is the initial velocity

t is the time taken

      A  = [tex]\frac{4 - 2}{2}[/tex]   = 1m/s²

Answer:

Fscos63

Explanation:

Given that a horizontal pole is attached to the side of a building. There is a pivot P at the wall and a chain is connected from the end of the pole to a point higher up the wall. There is a tension force F in the chain. What is the moment of the force F about the pivot P?

Taking the moment from the pivot point P, that means the moment at point p = 0

Then, if we consider the weight mg of the pole, according to the principle of equilibrium : sum of the upward forces equal to the sum of the downward forces.

Therefore, mg = Fsinø ....... (1)

Also, taking moment at point P

Let the length of the pole = s

The length of the weight of the pole = 1/2 S

Fscosø = mgs/2

The distance s will cancel out

2Fcosø = mg ...... (3)

Substitute mg in equation 1 into equation 3

2fcosø = fsinø

F will cancel out

Tanø = 2

Ø = tan^-1(2)

Ø = 63.4 degree

The moment of force F about pivot point P will be

Moment = force × distance

Moment = Fcos63 × S

Moment = Fscos63

The projectile is any object thrown into space upon which the only acting force is gravity. In other words, the primary force acting on a projectile is gravity. This doesn’t necessarily mean that the other forces do not act on it, just that their effect is minimal compared to gravity. The path followed by a projectile is known as a trajectory. A baseball batted or thrown and the instant the bullet exits the barrel of a gun are all examples of the projectile.

When a particle is thrown obliquely near the earth’s surface, it moves along a curved path under constant acceleration that is directed towards the center of the earth (we assume that the particle remains close to the surface of the earth). The path of such a particle is called a projectile and the motion is called projectile motion. Air resistance to the motion of the body is to be assumed absent in projectile motion.

In a Projectile Motion, there are two simultaneous independent rectilinear motions:

Along the x-axis: uniform velocity, responsible for the horizontal (forward) motion of the particle.

Along y-axis: uniform acceleration, responsible for the vertical (downwards) motion of the particle.

Accelerations in the horizontal projectile motion and vertical projectile motion of a particle: When a particle is projected in the air with some speed, the only force acting on it during its time in the air is the acceleration due to gravity (g). This acceleration acts vertically downward. There is no acceleration in the horizontal direction, which means that the velocity of the particle in the horizontal direction remains constant.

[tex]\sf~~~~~~~~~~~~~~~{\red{\underbrace{\underline{\green{projectile~motion}}}}}[/tex]

Projectile motion is a form of motion in which object or particle is thrown near earth's surface and it moves along a curved path under the action of gravity only.

Answer:

Explanation:

The velocity can be found by using the formula

[tex]v = \sqrt{ \frac{2k}{m} } \\ [/tex]

k is the kinetic energy

m is the mass

From the question we have

[tex]v = \sqrt{ \frac{2 \times 4116}{4200} } \\ = 1.4[/tex]

We have the final answer as

Hope this helps you

Answer:

The speed of the lift is 1.4 m/s

Explanation:

Kinetic Energy

Is the type of energy of an object due to its motion. It's proportional to the square of the speed and the mass.

The equation for the kinetic energy is:

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

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

It's given the mass of the lift as m=4,200 kg and its kinetic energy K=4,116 J. To calculate the speed (magnitude of velocity), we solve the formula for v as follows:

[tex]\displaystyle v=\sqrt{\frac{2k}{m}}[/tex]

[tex]\displaystyle v=\sqrt{\frac{2*4,116}{4,200}}[/tex]

[tex]\displaystyle v=\sqrt{1.96}[/tex]

v = 1.4 m/s

The speed of the lift is 1.4 m/s

Answer:

4km/hr

Explanation:

The given question is incomplete. The complete question is:

Estimate the volume of each ball. Use the formula [tex]v=\frac{4\pi\times r^3}{3}[/tex] where v is the volume and r is the radius. record the volume in table A of your student guide. The radius of the tennis ball is 2.1 cm and the radius of thr golf ball is 2.0 cm. What is the estimated volume of the table tennis ball in [tex]cm^3 [/tex] What is the estimated volume of the golf ball in

Answer: Volume of the tennis ball is [tex]38.8cm^3[/tex] and  Volume of the golf ball is [tex]33.5cm^3[/tex]

Explanation:

We have to find the Volume of tennis ball and golf ball by using the formula [tex]v=\frac{4\pi\times r^3}{3}[/tex]

Radius of the tennis ball = 2.1 cm

Radius  of the golf ball =2.0 cm.

Putting the value of radius in the formula , we get:

Volume of the tennis ball =  [tex]\frac{4\times 3.14\times (2.1cm)^3}{3} =38.8cm^3[/tex]

Volume of the golf ball =   [tex]\frac{4\times 3.14\times (2.0cm)^3}{3} =33.5cm^3[/tex]

Volume of the tennis ball is [tex]38.8cm^3[/tex] and  Volume of the golf ball is [tex]33.5cm^3[/tex]

it's  38.8 and 33.5 hope this helps

Answer:

A convex lens or converging lens focuses the light rays to a specific point whereas a concave lens or diverging lens diverges the light rays. When these lenses are combined, they produce sharper images. Most of the eyeglass lenses use combinations of convex and concave lenses.

Explanation:

W=f×d

=20×6

w=120 joule

Answer:

what's the question?........

Answer:

E = 50850[kJ]

Explanation:

To boil the water we must use the latent heat of vaporization. Also we need to multiply this value by the mass of the water.

[tex]E=m*H_{v}[/tex]

Where:

E = energy produced by heat [J]

m = mass = 225 [kg]

Hv = 226000 [J/kg]

[tex]E = 225*226000\\E = 50850000 [J]\\E=50850[kJ][/tex]

Answer:

because of Friction is always present.

Explanation:

In Newton's 1 law, an object will not change its motion unless a force acts on it.

The motion of a ball falling down through the atmosphere, or a model rocket being launched up into the atmosphere are both examples of Newton's first law. 

In Newton's 2 law, the force on an object is equal to its mass times its acceleration.

Riding your bicycle is a good example of this law of motion at work. ... Your leg muscles pushing pushing on the pedals of your bicycle is the force. When you push on the pedals, your bicycle accelerates.

In Newton's 3 law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.

For example, when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air.

Answer:

156.8 Joules

Explanation:

Work = Force x Displacement

Displacement = 2m

Force (force of gravity) = mass x acceleration due to gravity =  8Kg x 9.8m/s^2

= 78.4N

Work = FxD

Work = 78.4 N x 2m

Work = 156.8 N·m  OR 156.8 Joules

The amount of work done in lifting this box is equal to 156.8 Joules.

Given the following data:

Scientific data:

To calculate the amount of work that is done in lifting this box:

Mathematically, the work done by a person is calculated by using this formula:

[tex]Work\;done = Fd = mgd[/tex]

Where:

Substituting the given parameters into the formula, we have;

[tex]Work\;done = 8 \times 9.8 \times 2[/tex]

Work done = 156.8 Joules.

Read more on work done here: https://brainly.com/question/25573309

Answer:

down below

Explanation:

for a scale, kg is used, as well as grams

for force, newtons is used