Which of the following is true for valence electrons?
Valence electrons are always located in the outer most energy level.
Valence electrons are found only in radioactive isotopes.
Valence electrons are always located in the innermost energy level
Valence electrons are found only in negatively charged ions.

Answer:Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards.

Explanation:

Answer:

The fraction of the object that is below the surface of the water is ¹⁷/₂₀

Explanation:

Given;

specific gravity of the object, γ = 0.850

Specific gravity is given as;

[tex]specific \ gravity = \frac{density \ of the \ object}{density \ of \ water}\\\\0.85= \frac{density \ of the \ object}{1000 \ kg/m^3} \\\\density \ of the \ object = 850 \ kg/m^3[/tex]

Fraction of the object's weight below the surface of water is calculated as;

[tex]= \frac{850}{1000} \ \times\ 100\%\\\\= 85 \% \\\\= \frac{17}{20}[/tex]

Therefore, the fraction of the object that is below the surface of the water is ¹⁷/₂₀

Answer:

500kg

Explanation:

....................

Answer:

500Kg

Explanation:

1 kg = 10N

? =5000N

5000N÷10N * 1Kg = 500Kg

Notice that both of those points are 3 units below the x-axis. So the line is horizontal ... its slope is zero.

Answer:

0.45 s

Explanation:

Step 1: Given and required data

Step 2: Calculate the time that it will take for the book to hit the floor (t)

The book undergoes a Uniformly Accelerated Motion. We can calculate the time required to reach the floor using the following suvat equation.

s = u × t + 1/2 × a × t²

s = 0 m/s × t + 1/2 × a × t²

s = 1/2 × a × t²

t = √(2s/a)

t = √(2 × 1 m/9.8 m/s²)

t = 0.45 s

Answer:

20 m/s.

Explanation:

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

Distance travelled = 600 m

Time taken = 30 s

Speed =?

Speed can be defined as the distance travelled per unit time. Mathematically, it is expressed as:

Speed = Distance /time

With the above formula, we can easily calculate the speed of the bus as follow:

Distance travelled = 600 m

Time taken = 30 s

Speed =?

Speed = Distance /time

Speed = 600 / 30

Speed = 20 m/s

Therefore, the speed of the bus is 20 m/s.

Answer:

Q is the amount of energy released or absorbed during the change of phase of the substance (in kJ or in BTU), m is the mass of the substance (in kg or in lb), and. L is the specific latent heat for a particular substance (kJ kg−1 or in BTU lb−1), either Lf for fusion, or Lv for vaporization.

I hope this helps∪ω∪

Answer:

A

Explanation:

Answer:

[tex]5.33\ m/s[/tex]

Explanation:

[tex]We\ know\ that,\\Momentum=Mass*Velocity\\p=mv\\Hence,\\Lets\ first\ consider\ the\ case\ of\ the\ two\ balls\ 'Before\ Collision':\\\\Mass\ of\ the\ green\ ball=0.2\ kg\\Initial\ Velocity\ of\ the\ green\ ball=5\ m/s\\Initial\ Momentum\ of\ the\ green\ ball=5*0.2=1\ kg\ m/s\\\\Mass\ of\ the\ pink\ ball=0.3\ kg\\Initial\ Velocity\ of\ the\ pink\ ball=2\ m/s\\Initial\ Momentum\ of\ the\ pink\ ball=0.3*2=0.6\ kg\ m/s\\\\Total\ momentum\ of\ both\ the\ balls\ 'Before\ Collision'=1+0.6=1.6\ kg\ m/s[/tex]

[tex]Hence,\\Lets\ now\ consider\ the\ case\ of\ the\ two\ balls\ 'After\ Collision':\\\\Mass\ of\ the\ green\ ball=0.2\ kg\\Final\ Velocity\ of\ the\ green\ ball=0\ m/s\\Final\ Momentum\ of\ the\ green\ ball=0\ kg\ m/s\\\\Mass\ of\ the\ pink\ ball=0.3\ kg\\Final\ Velocity\ of\ the\ pink\ ball=v\ m/s\\Final\ Momentum\ of\ the\ pink\ ball=0.3*v=0.3v\ kg\ m/s\\\\Total\ momentum\ of\ both\ the\ balls\ 'After\ Collision'=0+0.3v=0.3v\ kg\ m/s[/tex]

[tex]As\ we\ know\ that,\\Through\ the\ law\ of\ conservation\ of\ momentum,\\In\ an\ isolated\ system:\\Total\ Momentum\ Before\ Collision=Total\ Momentum\ After\ Collision\\Hence,\\1.6=0.3v\\v=\frac{1.6}{0.3}=5.33\ m/s[/tex]

Although the semi truck certainly has a larger mass, it is not in motion and therefore does not have any momentum. The bicycle however has both mass and velocity and therefore has the larger momentum of the pair.

Answer: 176.4 J

Explanation:

Complete Question

The complete question is shown on the first uploaded image

Answer:

Explanation:

From the question we are told

   The amplitude of the lateral  force is  [tex]F = 25 \ N[/tex]

   The frequency is   [tex]f = 1 \ Hz[/tex]

   The mass of the bridge per unit length is  [tex]\mu = 2000 \ kg /m[/tex]

    The length of the central span is  [tex]d = 144 m[/tex]

     The oscillation amplitude of the section  considered at the time considered is  [tex]A = 75 \ mm = 0.075 \ m[/tex]

      The time taken for the undriven oscillation to decay to [tex]\frac{1}{e}[/tex]  of its original value is  t = 6T

Generally the mass of the section considered is mathematically represented as

            [tex]m = \mu * d[/tex]

=>        [tex]m = 2000 * 144[/tex]

=>        [tex]m = 288000 \ kg[/tex]

Generally the oscillation amplitude of the section after a  time period  t is mathematically represented as

                 [tex]A(t) = A_o e^{-\frac{bt}{2m} }[/tex]

Here b is the damping constant and the [tex]A_o[/tex] is the amplitude of the section when it was undriven

So from the question  

               [tex]\frac{A_o}{e} = A_o e^{-\frac{b6T}{2m} }[/tex]

=>            [tex]\frac{1}{e} =e^{-\frac{b6T}{2m} }[/tex]

=>          [tex]e^{-1} =e^{-\frac{b6T}{2m} }[/tex]

=>           [tex]-\frac{3T b}{m} = -1[/tex]

=>         [tex]b = \frac{m}{3T}[/tex]

Generally the amplitude of the section considered is mathematically represented as

           [tex]A = \frac{n * F }{ b * 2 \pi }[/tex]

=>       [tex]A = \frac{n * F }{ \frac{m}{3T} * 2 \pi }[/tex]

=>       [tex]n = A * \frac{m}{3} * \frac{2\pi}{25}[/tex]

=>       [tex]n = 0.075 * \frac{288000}{3} * \frac{2* 3.142 }{25}[/tex]

=>       [tex]n = 1810 \ people[/tex]

If the box is moving at constant velocity, net force must be zero, so:

F + fr = 0

fr = -F

fr = -40 N

Question 6

C. 72.1 N

Its simply the newton Third law, whenever two objects interact, they exert equal and opposite forces on each other.

Question 7

D. Maria is incorrect because the cart's velocity has changed

The car is accelerating so, It is not in dynamic equilibrium. Remember that by the Newton Second Law:

F = ma

The cart is in dynamic equilibrium. The correct options for the two question are:

6. C

7. A

6.) Given that a 61.0 kg grocery cart is sitting at rest. And Xavier applied 72.1 Newtons of force on the cart.

According to Newton's third law of motion which state that, in every action, there will be equal and opposite reaction. The magnitude of force That the cart exert back on Xavier's hand will be opposite and equal to the force applied. which is negative 72.1 N

7.) If the grocery cart is moving in a constant velocity, then it will achieve a dynamic equilibrium. In this scenario, the air resistance force balances with the applied force.

Therefore,  Maria is correct because the cart is traveling at a constant velocity while experiencing balanced forces.

Learn more about equilibrium of forces here: https://brainly.com/question/9076091

Answer:

here are the options.

Answer:

the energy that is associated with temperature or D

Explanation:

Hope this helps

Question 4

B. Toby is correct because the rock is experiencing a negative acceleration, causing its positive velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.

Question 5

At the maximum height, velocity is 0, so:

v = v₀ - gt

0 = 14.75 - 9.8t

t = 14.75/9.8

t = 1.5 s    (OPTION A)

4). In the given situation, the assertion that could be made regarding Toby would be:

B). Toby is correct because the rock is experiencing a negative acceleration, causing its positive velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.

5). The time that would be taken by the rock to attain its greatest height would be:

1.5 second

4). Tobby correctly states as rock would be undergoing a -ve acceleration which leads its +ve velocity to fall by the time rock attains the velocity of 0 m/s.

Thus, option B is the correct answer.

5). Given that,

Initial velocity([tex]v_{0}[/tex]) = 14.75 m/s

As we know,

Velocity remains 0 m/s at the greatest height,

So,

Velocity(v) [tex]= v_{0} - gt[/tex]

where

[tex]0 = 14.75 - 9.8t[/tex]

⇒ [tex]t = 14.75/9.8[/tex]

 ∵ [tex]t = 1.5 s[/tex]

Learn more about "Velocity" here:

brainly.com/question/18084516

Answer:

ight bet

Explanation:

Answer:sometimes it commits to how it will happen

Explanation:

Answer:

Atmospheric pressure increases density

Explanation:

Atmospheric pressure decreases the volume of space, since volume is inversely proportional to density, density will increase.

lost of nutrition in human

Answer:

True

Explanation:

Obesity and stress are confirmed risk factors for CHD

Answer:

v = 15.65 m/s

Explanation:

We use conservation of mechanical energy between initial (i) and final (f) states:

Pi + KEi = Pf + KEf

At the top of the cave at the instant the bat starts to fall, there is only potential energy since the bat's velocity is zero.

Pi = m g h = 600 J

and the KEi = 0 J (no velocity)

Knowing the height of the cave's roof (12.8 m) , we can find the mass of the bat:

m = 600 J / (g 12.5) = 4.9 kg

Using conservation of mechanical energy, the final state is:

Pf + KEf = 600 J

with Pf = 0 (just touching the ground)

KEf= 1/2  4.9 (v^2)

and we solve for the velocity:

600 J = 0 + 1/2  4.9 (v^2)

v^2 = 600 * 2 / 4.9 = 244.9

v = 15.65 m/s

Answer:

The force will be "[tex]9.8\times 10^{-3} \ N[/tex]".

Explanation:

The given values are:

Mass,

m = 1 gram

Angle,

Ф = 20°

As we know,

⇒ [tex]F=mg[/tex]

On substituting the given values in the above expression, we get

⇒     [tex]=(1.0\times 10^{-3})(9.8)[/tex]

⇒     [tex]=9.8\times 10^{-3} \ N[/tex]

Answer:

Q = 12.5 kJ

Explanation:

Given that,

Mass of water, m = 50 mL = 0.05 kg

The temperature changes from 0 degree Celsius to 60 degree Celsius.

We need to find how much energy she use to heat the water. The energy required to heat the water is given by :

[tex]Q=mc\Delta T[/tex]

Where c is specific heat of water, c = 4186 J/kgºC

[tex]Q=0.05\times 4186 \times (60-0)\\\\=12558\ J[/tex]

or

Q = 12.5 kJ

So, the energy used to heat th water is 12.5 kJ.

Answer:

h = 0.697 [m]  

Explanation:

To solve this problem we must use the energy conservation theorem, where it tells us that kinetic energy is converted to potential energy or vice versa.

[tex]E_{kinet}=E_{pot}[/tex]

where:

Ekinet = kinetic energy [J]

Epot = potential energy [J]

[tex]\frac{1}{2}*m*v^{2}=m*g*h\\0.5*(3.7)^{2} =9.81*h\\h =(6.845)/9.81\\h = 0.697 [m][/tex]

Answer:

1) - They should move away because its cold

2) - You can get hypothermia......

Explanation:

Answer:

d) the second law of thermodynamics

Explanation:

Here we take an example

The entropy represents a measurement of the energy dispersal in the system. Also, the campfire would an entropy example. The burning of the solid wood and then it became the ash, smoke and gases this all would be spread the energy to the outward as compared to the solid fuel

Therefore as per the given statement, the correct option is d.

Answer:

Speed. I am speed.

Explanation:

The FitnessGram Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. A single lap should be completed each time you hear this sound. Remember to run in a straight line, and run as long as possible.

Answer:

388.07 J

Explanation:

Answer:

C) 388.07

Explanation:

It is a spring therefore, there must be Elastic potential energy. Now what is the formula for elastic potential energy? It is 1/2 *k *x^2

K=spring constant

x= displacement  

1/2=.5 (hate fractions)

Now, Displacement simply means (how much was it moved?) So, that means subtract.

87-20= 67   x=67

Next, do x^2 (so you don't make a mistake by squaring everything :)  )

67*67=4,489

NOW, do....

.5*1729*4,489=3,880,740.5

Now convert to Joules, I just did 3,880,740.5  / 10^3 = 3880.745

round to 3880.7 J  

                                                                ~There you go loves !

Answer:

The electrons are on the outer shell, there are 10 of them.

Explanation:

There are two in the inner shell and eight in the outer shell, giving us a total of 10 electrons

Answer:

the ability to learn, emotional knowledge, creativity, and adaptation to meet the demands of the environment effectively

Normal force is the force exerted when an object is on an surface. So an example could be a pile of books on top of a table.