Which region contains the alkaline earth metal family of elements? A, B, C or D?

Answer:

68.88 m/s

Explanation:

downstream speed = 8+1.9=9.9 m/s

upstream speed = 8-1.9= 6.1 m/s

Therefore, total time taken would be 260/9.9+260/6.1 = 26.26+42.62 =

68.88 m/s

Answer:

The moment of inertia of disc about own axis is 1 kg-m².

Explanation:

Given that,

Mass of ring m= 1 kg

Moment of inertia of ring at diameter [tex](I_{r})_{d}=1\ kg\ m^{2}[/tex]

The radius of metallic ring and uniform disc both are equal.

So, [tex]R_{r}=R_{d}[/tex]

We need to calculate the value of radius of ring and disc

Using theorem of perpendicular axes

[tex](I_{r})_{c}=2\times (I_{r})_{d}[/tex]

Put the value into the formula

[tex](I_{r})_{c}=2\times1[/tex]

[tex](I_{r})_{c}=2\ kg\ m^2[/tex]

Put the value of moment of inertia

[tex]MR_{r}^2=2[/tex]

[tex]R_{r}^2=\dfrac{2}{M}[/tex]

Put the value of M

[tex]R_{r}^2=\dfrac{2}{1}[/tex]

So, [tex]R_{r}^2=R_{d}^2=2\ m[/tex]

We need to calculate the moment of inertia of disc about own axis

Using formula of moment of inertia

[tex]I_{d}=\dfrac{1}{2}MR_{d}^2[/tex]

Put the value into the formula

[tex]I_{d}=\dfrac{1}{2}\times1\times2[/tex]

[tex]I_{d}=1\ kg\ m^2[/tex]

Hence, The moment of inertia of disc about own axis is 1 kg-m².

Answer:

4.44 m/s^2

Explanation:

A 15-kg wagon is pulled to the right across a surface by a tension of 100 newtons at an angle of 30 degrees above the horizontal. A frictional force of 20 newtons to the left acts simultaneously.The acceleration of the wagon 4.44 m/s².

The rate at which an item changes its velocity is known as acceleration, a vector quantity. If an object's velocity is changing, it is acceleration.

Given in the question a 15 kg wagon is pulled to the right across a surface by a tension of 100 newtons at an angle of 30 degrees above the horizontal. A frictional force of 20 newtons to the left acts simultaneously, then the acceleration is  4.44 m/s².

The acceleration of the wagon 4.44 m/s².

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Answer:

air resistance and gravity.

Explanation:

When the ball is falling down at terminal velocity, the velocity is constant.

This means that the net force acting on the ball will be zero (there is no acceleration)

In this situation, there are only two forces that can act on the ball.

The gravitational force, that pulls the ball down.

The air resistance which opposes to the movement of the ball and increases in magnitude as the velocity of the ball increases.

Then there is a point where the velocity of the ball is such that the air resistance is equal in magnitude to the acceleration, and then the net force becomes zero.

Then the two forces that need to be included in this diagram are the air resistance and gravity.

Answer:

The evidence that the universe is expanding comes with something called the red-shift of light. Light travels to Earth from other galaxies. As the light from that galaxy gets closer to Earth, the distance between Earth and the galaxy increases, which causes the wavelength of that light to get longer. Distant galaxies are getting further away hinting at a point of origin. The composition of all observed matter in this universe points at a common origin point for all matter in the universe.

The three crucial evidences that supported the Big Bang theory are the CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.

Big Bang theory is one of the important theory scientists used in earliest to describe the origin of universe and the phenomenon of evolution.

Here,

2. The Big Bang theory described the origin of universe as an expansion from an atmosphere of high density and extreme temperature which lead to a huge explosion of matter known as the  'Big Bang' and thus creation of  the universe.

The three crucial evidences that supported the Big Bang theory are:

The CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.

3.(a) Light spectra was an important factor that supported the Big Bang theory mainly by the phenomenon called Doppler shift. Doppler shift occurs when stars move away, they get shifted to longer wavelength. This phenomenon is called red-shift or Doppler's Red shift. This was applicable in the case of Big Bang theory such that the theory claimed that, as a result of explosion which is the Big Bang, the material particles move away. This was similar to the red shift.

(b) The motion of distant galaxies was an evidence of the expansion of universe and soo the Big Bang theory. It was explained in such a way that, as the galaxies move away from us, it shows the more expansion of universe and the time duration since the origin of universe.

(c) The composition of matter in the universe was an important evidence that supported the Big Bang theory. The composition of universe that there is high abundance of hydrogen and helium in the atmosphere was claimed by the Big Bang theory.

Hence,

The three crucial evidences that supported the Big Bang theory are the CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.

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Answer:the answer is C aluminum foil

Explanation:

Answer:

θ = 26.6°

Explanation:

Formula for maximum height is;

h = u²sin²θ/2g

We are told maximum height is 25 m, thus;

u²sin²θ/2g = 25 - - - - (eq 1)

Formula for horizontal range is;

R = u²sin2θ/g

In Mathematics, sin2θ = 2sinθcosθ

So; R = 2u²sinθcosθ/g

R = 2u²sinθcosθ/g

We are given Horizontal range = 200 m.

Thus;

2u²sinθcosθ/g = 200 - - - - (eq 2)

Divide eq 1 by eq 2 to get;

200/25 = 4cosθ/sinθ

8 = 4cosθ/sinθ

4/8 = sinθ/cosθ

0.5 = tan θ

θ = tan^(-1) 0.5

θ = 26.6°

Answer:

i think its D

Explanation:

Answer:

y = 160t - 16t²

Explanation:

Using y = ut -1/2gt² where y = height of heavy rock above the ground, u = initial launch velocity of rock = 160 ft/s, g = acceleration due to gravity = 32 ft/s² and t = time.

So, substituting the values of the variables into y, we have

y = (160 ft/s)t -1/2 × 32 ft/s² × t²

y = (160 ft/s)t - (16 ft/s²)t²

y = 160t - 16t²

So, the height function is y = 160t - 16t²

Answer:

v = 24.49[m/s]    

Explanation:

We must remember that kinetic energy can be calculated by means of a mathematical expression, which relates kinetic energy to mass and velocity

[tex]E_{kin}=\frac{1}{2}*m*v^{2} \\[/tex]

where:

Ekin = kinetic energy = 12000 [J]

m = mass = 40 [kg]

v = velocity [m/s]

[tex]12000=\frac{1}{2} *40*v^{2}\\24000=40*v^{2}\\600=v^{2}\\v=\sqrt{600}\\v=24.49[m/s][/tex]

Answer:

8.6m

Explanation:

Step one:

given data

we are given two displacement vectors of magnitudes 5 and 7m

Let us assume they are in the same direction and they are acting perpendicular to each other.

Step two:

The magnitude of the vector sum is the resultant vector

which is  found by

R^2=5^2+7^2

R^2= 25+49

R^2=74

R=√74

R=8.6m

Answer:

zero

Explanation:

no distance has moved while holding the sheet...so no distance means no workdone..no workdone means no power...

Answer:

Velocity is the rate at which the position changes. The average velocity is the displacement or position change per time ratio.

Explanation:

Answer:

The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction of motion (e.g. 60 km/h to the north).

Other units: mph, ft/s

In SI base units: m/s

Explanation:

i dont know if this helps.

Answer:

1)1*20=20

2)-30/3=- -10

3)velocity of the object 1=v1=4*V2

4) kg m/ s

5) momentum of the system= 12 kg m/ s

Answer:

Explanation:

The force engine exert on the car can be found by using the formula

[tex]f = \frac{w}{d} \\ [/tex]

w is the workdone

d is the distance

From the question we have

[tex]f = \frac{520}{260} = 2 \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

P = 271 nW

Explanation:

       [tex]I = \frac{P}{A} =\frac{P}{4*\pi *r^{2} } (1)[/tex]

       [tex]P = I*4*\pi *r^{2} = 6.0e-10 W/m2 * 4 * \pi *(6m)^{2} =271 nW (2)[/tex]

Answer:

I think it is the answer A

Explanation:

Alcohol won't stimulate the central nervous system and the peripheral nervous system because the fact that the brain and the nervous system are affected can lead to many consequences: disorders of vision, hearing, motor coordination ...

Alcohol will therefore have a damaging effect, it will therefore sedate the nervous system.

Answer:A

Explanation:sedates

Answer:

3, it's the igneous rock, sedimentary rock, and metamorphic rock i believe

Explanation:

Answer:

igneous, sedimentary, and metamorphic.

Explanation:

Answer:

Force = -50000 Newton

Explanation:

Given the following data;

Initial velocity, u = 30 m/s

Final velocity, v = 20 m/s

Time = 0.2secs

Mass = 1000 kg

First of all, we have to solve for its acceleration.

Acceleration = (v - u)/t

Substituting into the equation, we have

Acceleration = 20 - 30)/0.2

Acceleration = -10/0.2

Acceleration = -50m/s²

To find the force;

Force = mass * acceleration

Force = 1000 * (-50)

Force = -50000 Newton. The value of the force is negative because it stopped the motion of the car.

Therefore, the barrier applied a force of -5,0000 Newtons to stop the car.

Answer: -50000

Explanation:

Answer:

E = 4.7 x [tex]10^{-19}[/tex] Joules

Explanation:

Solution:

The wavelength of a particular color of violet light = 417 nm

What is the energy = ?

In order to calculate energy, we will use the following formula:

E = hf

where, f = frequency = 1/wavelength = c/λ

where c = speed of light = 299 792 458 m / s or 3 x [tex]10^{8}[/tex] m/s

where h = Plank's constant = 6.62x [tex]10^{-34}[/tex] [tex]m^{2}[/tex] kg / s

So,

λ = 417 nm

1 nm = [tex]10^{-9}[/tex] m

so,

λ = 417 x [tex]10^{-9}[/tex] m

Now, just plug in the values to calculate the energy of this wavelength of light.

E = hc/λ

E = ( 6.62x [tex]10^{-34}[/tex] ) (299 792 458) / (417 x [tex]10^{-9}[/tex] )

E = 0.047 x[tex]10^{-17}[/tex]

E = 4.7 x [tex]10^{-19}[/tex] Joules

Answer:

Use the stairs

Explanation:

This is easier because if you go on the stairs you can rest if you get tired but if you go on the inclined plane then the weight of the jugs will make you slower than you already are and you may end up going back down instead of up where you wanna go.

Answer:

B. some isotopes are stable and others are unstable. unstable isotopes decay by emitting various subatomic particles and radiation.

Explanation:

test gave me the answer so yeah :/ XD

Answer:

I believe it to be option A

Explanation:

Answer:

W = 41.45 Kcal

Explanation:

Given that,

The mass of a person, m = 75 kg

He climbs 248 steps to the top of the Cape Hatteras lighthouse, a total climb of 59 m.

We need to find how many calories does he or she burn.

Work done = Fd

d is displacement

⇒ W = 75 ×9.8 ×59

= 43365  J

Let the efficiency is 0.25.

[tex]W=\dfrac{43365}{0.25}\\\\=173460\ J\\\\\text{or}\\\\=41.45\ kcal[/tex]

So, 41.45 Kcal is burned by the person.

Answer:

77000 J

Explanation:

Formula for the heat energy is;

Q = m•c•Δt

We are given;

mass; m = 2 kg

Change in temperature; Δt = 110 - 10 = 100 °C

From online values, specific heat capacity of copper is; c = 385 J/kg.°C

Thus;

Q = 2 × 100 × 385

Q = 77000 J

Answer:

heat = 20 Kcal

Explanation:

Answer:

This is very true

Explanation:

The force from impact can easily change it to expanse in a different direction.

I hope this helped you very much :)

Answer:

yes

Explanation:

Answer:

y e p  

Explanation:

Answer:

fixed pulley: A pulley system in which the pulley is attached to a fixed point and the rope is attached to the object. ... movable pulley: A pulley system in which the pulley is attached to the object; one end of the rope is attached to a fixed point and the other end of the rope is free.

Explanation: