An echo is sound that returns to you after being reflected from a distant surface (e.g., the side of a cliff). Assuming that the distances involved are the same, an echo under water and an echo in air return to you _____________________

a. at different times, the echo under water returning more slowly.
b. at different times, the echo under water returning more quickly.
c. at the same time

When calcium reacts with chlorine. Electrons move from the calcium atoms to the chlorine atoms. Option D is correct.

When one or more chemicals are transformed into one or more other compounds, a chemical reaction occurs.

In an ionic compound, calcium chloride is present. To build a complete outer shell of electrons, the calcium atom loses two electrons and each chlorine atom obtains one.

When calcium combines with chlorine, it forms calcium chloride. From the calcium atoms to the chlorine atoms, electrons travel.

Hence, option D is correct.

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I have assumed a weight of 120 N on Earth.

Answer:

The object weighs 20 N on the moon

Explanation:

Weight

The weight of an object depends on the mass m of the object and the acceleration of gravity g of the place they are in.

The formula to calculate the weight is:

W = m.g

If g_e is the acceleration of gravity on Earth, and g_m is the acceleration of gravity on the moon, we know:

[tex]g_m=1/6 g_e[/tex]

Dividing by ge:

[tex]g_m/g_e = 1/6[/tex]

An object of weight We=120 N on planet Earth has a mass of:

[tex]m = 120 / g_e[/tex]

Multiplying by gm:

[tex]m.g_m=120 g_m/g_e[/tex]

Substituting the ratio of accelerations of gravity:

[tex]m.g_m=120 * 1/6[/tex]

Since m.gm is the weight on the Moon Wm:

[tex]W_m=20~N[/tex]

The object weighs 20 N on the moon

Assuming the acceleration due to gravity on the moon is exactly one-sixth of the acceleration due to gravity on Earth, the weight of the object on the moon would be one-sixth of its weight on Earth.

Knowing an object's weight on Earth and applying the ratio of the acceleration caused by gravity on the moon to that on Earth will allow us to determine an object's weight on the moon.

Assume that the object's weight on Earth is W (in newtons).

On Earth, the acceleration due to gravity = 9.8 [tex]m/s^2[/tex].

On the moon, = (1/6) * 9.8 [tex]m/s^2[/tex] = 1.6333 [tex]m/s^2[/tex]

Weight = Mass * Acceleration due to gravity

Weight on the moon = W * (1/6)

Thus, the weight of the object on the moon would be one-sixth of its weight on Earth.

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Answer:

a = 1.152s

b = 0.817 m

c = 7.29m/s

Explanation: let the following

From the first equation of linear motion

V = u+at..........1

parameters be represented as :

t = Time taken

v = Final velocity

a = Acceleration due to gravity = 9.8m/s²

u = Initial velocity = 4 m/s

s = Displacement

V = 0

Substitute the values into equation 1

0 = 4-9.8(t)

-4 = -9.8t

t = 4/9.8

t = 0.408s

From : s = ut+1/2at^2.........2

S = 4×0.408+0.5(-9.8)×0.408^2

S= 1.632-4.9(0.166)

S = 1.632-0.815

S = 0.817m

Her highest height above the board is 0.817 m

Total height she would fall is 0.817+1.90 = 2.717 m

From equation 2

s = ut+1/2at^2

2.717 m = 0t+0.5(9.8)t^2

2.717 m = 0+4.9t^2

2.717 m = 4.9t^2

2.717/4.9 = t^2

0.554 =t^2

t =√0.554

t = 0.744s

Hence, her feet were in the air for 0.744+0.408seconds

= 1.152s

Also recall from equation 1

V= u+at

V = 0+9.8(0.744)

V = 7.29m/s

Hence, the velocity when she hits the water is 7.29m/s

Finally,

a = 1.152s

b = 0.817 m

c = 7.29m/s

Answer:

The surface must be a good absorber of light. Spectra of the planets proved that methane in the atmospheres of these planets is what absorbs red light.

Explanation:

Answer: 4100 Mpc

Explanation:

Since H o = 70 km/s/Mpc

Redshift z = 5.82

Recessional velocity vr = 287,000 km/s

Then, the distance to the galaxy in light years will be:

= Recessional velocity / H o

= 287000 / 70

= 4100 Mpc

Answer:

Explanation:

a) Maximum height id expressed as;

H = u²sin² theta/2g

H = 36.6²(sin42.2)²/2(9.8)

H = 1,339.56(0.6717)/19.6

H = 899.81/19.6

H = 45.91m

Hence the maximum height is 45.91m

b) The Time of flight is the total time in air expressed as;

T = 2usin theta/g

T = 2(36.6)sin42.2/9.8

T = 73.2sin42.2/9.8

T = 49.17/9.8

T = 5.017secs

Hence the total time in air is 5.017scs

c) Range = U²sin2(theta)/g

Range = 36.6²sin2(42.2)/9.8

Range = 1,339.5(0.9952)/9.8

Range = 1,333.11/9.8

Range = 136.03m

Hence the range is 136.03m

d) USing the rime of flight formula;

T =2Usintheta/g

1.5 = 2Usin42.2/9.8

2Usin42.2 =1.5*9.8

2Usin42.2 = 14.7

U = 14.7/2sin42.2

U = 14.7/1.3434

U = 10.94m/s

Hence the speed of the projectile is 10.94m/s

Answer:

2) deflection must be towards the negative side of the voltage.

4) the correct statements are: b and c

Explanation:

2) This question is based on Faraday's law of induction, when we introduce a magnet in a solenoid an induced current is produced that generates a voltage that is given by

           E = - N d [tex]\phi_{B}[/tex] / dt

where [tex]\phi_{B}[/tex] = B. A

The bold are vectors

Therefore, when applying this formula to our case, the induction lines of the magnetic field increase as we approach the solenoid, as the South pole approaches the lines are in the direction of the magnet, therefore the normal to the solenoid that has an outgoing direction and the magnetic field has 180º between them and the cos 180 = -1; consequently the deflection must be towards the negative side of the voltage.

4) From the Faraday equation we can see that the inductive electromotive force depends

* The magnitude of B that changes over time

* The area of ​​the loop that changes over time

* The angle between B and the area that changes over time

* A combination of the above

With this analysis we will review the different alternatives given

a) False. It takes a temporary change and an absolute value of B

b) True. As the speed decreases, the change in B decreases, that is, dB / dt decreases

c) True. The current is induced in each turn, if there is a smaller number the total current will be smaller

d) False. A temporary change of area is needed, in addition to increasing the area the current increases

We can see that the correct statements are: b and c

Answer:

Zero.

Explanation:

Answer:

by counting each individual atom and making sure the number of each kind of atom is the same in the reactants and the products. - This is the answer.

Explanation:

Answer:

its A(by counting each individual atom and making sure the number of each kind of atom is the same in the reactants and the products

Explanation:

Answer:

1) k = 10 [N/m]

2) a-) x = 0.4 [m]

b)  x = 0.075 [m]

Explanation:

To be able to solve this type of problems that include springs we must use Hooke's law, which relates the force to the deformed length of the spring and in the same way to the spring coefficient.

F = k*x

where:

F = force [N] (units of Newtons]

k = spring constant  [N/m]

x = distance = 10 [cm] = 0.1 [m]

Now, the weight is equal to the product of the mass by the gravity

W = m*g = F

where:

m = mass = 100 [g] = 0.1 [kg]

g = gravity acceleration = 10 [m/s²]

F = 0.1*10 = 1 [N]

Now clearing k

k = F/x

k = 1/0.1

k = 10 [N/m]

2)

a ) if the force is 4 [N]

clearing x

x = F/k

x = 4/10

x = 0.4 [m]

m = 75 [g] = 0.075 [kg]

W = m*g = F

F = 0.075*10 = 0.75 [N]

x = .75/10

x = 0.075 [m]

Answer:

Yes, geothermal energy is a renewable energy resource because the water can be heated by pumping it through the rocks.

Answer:

Vₓ = -93.96 m/s

Vy = 34.2 m/s

Explanation:

The x-component of the velocity vector can be given as follows:

Vₓ = V Cos θ

where,

Vₓ = x-component of velocity vector = ?

V = Magnitude of Velocity Vector = 100 m/s

θ = Angle with positive x-axis = 160°

Therefore,

Vₓ = (100 m/s)Cos 160°

Vₓ = -93.96 m/s

The y-component of the velocity vector can be given as follows:

Vy = V Sin θ

where,

Vy = y-component of velocity vector = ?

V = Magnitude of Velocity Vector = 100 m/s

θ = Angle with positive x-axis = 160°

Therefore,

Vy = (100 m/s)Sin 160°

Vy = 34.2 m/s

Answer:

The images produced by a convex mirror are smaller than the object it reflects. The image produced by a concave lens is always virtual. The image in a convex mirror is always upright and is smaller than the object.

Explanation:

:)

Answer:

by a rocking chair, a bouncing ball, a vibrating tuning fork, a swing in motion, the Earth in its orbit around the Sun, and a water wave.

Explanation:

Answer:

It will be the same for both

Explanation:

from this question we have one similarity between these two spheres.

- they are both made from the same material,

The difference between both spheres is that:

- one of the spheres has its diameter to be twice as large as that of the other one.

We are to say the sphere with the greater bulk modulus.

If the material is the same thenthe Bulk modulus is also the same. It is not dependent on the material since it is a constant for that materia

Therefore the correct answer is:

It will be the same for both spheres.

Answer:

1000x Newton

Explanation:

Step one

given data

acceleration= 1000 m/s²

The question did not specify the mass of the mass of the space ship.

So, let's assume the mass is x kg

Step two:

Required is the force F in Newton

From Newtons first law, it states that a body will continue to be at rest or uniform motion unless acted upon by a force.

F=mass x Acceleration

F=ma

Substituting our given data we have

F=1000x Newton

Answer:

T' = 865.15 °C

Explanation:

In order for the copper collar to just slip on the steel shaft the, assuming are heated simultaneously, we must find the final parameters of both and equate them. Because the final diameters of both must be same for the slipping to occur.

FOR COPPER COLLAR:

dc' = dc(1 + ∝c*ΔT)

where,

dc' = final diameter of copper ring

dc = initial diameter of copper ring = 5.98 cm

∝c = coefficient of linear expansion for copper = 16 x 10⁻⁶ °C⁻¹

ΔT = Change in Temperature

Therefore,

dc' = (5.98 cm)[1 + (16 x 10⁻⁶ °C⁻¹)ΔT]   ------------- equation (1)

FOR STEEL SHAFT:

ds' = ds(1 + ∝s*ΔT)

where,

ds' = final diameter of steel shaft

ds = initial diameter of steel shaft = 6 cm

∝s = coefficient of linear expansion for steel = 12 x 10⁻⁶ °C⁻¹

ΔT = Change in Temperature

Therefore,

dc' = (6 cm)[1 + (12 x 10⁻⁶ °C⁻¹)ΔT]   ------------- equation (2)

Comparing equation (1) and equation (2):

(5.98 cm)[1 + (16 x 10⁻⁶ °C⁻¹)ΔT] = (6 cm)[1 + (12 x 10⁻⁶ °C⁻¹)ΔT]

(5.98 cm/6 cm)[1 + (16 x 10⁻⁶ °C⁻¹)ΔT] = [1 + (12 x 10⁻⁶ °C⁻¹)ΔT]

0.9967 + (1.59 x 10⁻⁵ °C⁻¹)ΔT = 1 + (12 x 10⁻⁶ °C⁻¹)ΔT

1 - 0.9967 = [(15.9 -12) x 10⁻⁶ °C⁻¹]ΔT

0.0033/3.9 x 10⁻⁶ °C⁻¹ = ΔT

ΔT = 846.15 °C

but,

ΔT = T' - T = T' - 19°C = 846.15°C

T' = 846.15 °C + 19 °C

T' = 865.15 °C

290m

The light always travels in a straight line.

At high noon, the ray from the sun is 2° from the vertical axis.

tan θ = (Opposite side)/(Adjacent side)

On applying above trigonometric formula, we get,

tan 2 = 10/h

0.035 = 10/h

∴ h = 10/0.035 = 290 m

Answer:

0.00033333333

Explanation:

Answer:

Explanation:

step one:

given data

velocity v=34.2m/s

time t= 8.7s

Step two

Required is the distance the cheetah has covered on the condition

we know that speed= distance/time

make distance subject of formula we have

distance= velocity *time

distance= 34.2*8.7

distance = 297.54m

Therefore the displacement the cheetah covered at that velocity

is 297.54m

Answer:

The time taken by the ant is 1204.82 seconds or 20.08 minutes

Explanation:

Given:

Speed of the ant (s) = 0.083 m/s

Distance traveled by the ant (D) = 100 m

We know that distance traveled by a body is equal to the product of the speed of the body and the time taken for its travel.

Let the time taken by the ant be 't' seconds.

Now, as per the formula:

Distance = Speed × Time

⇒ 100 m = 0.083 m/s × t

⇒ [tex]t = (100\ m)/(0.083\ m/s)[/tex]

[tex]\therefore t=1204.82\ s[/tex]

Now, we know that,

60 seconds = 1 minute

So, 1 second = [tex]\frac{1}{60}\ min[/tex]

Therefore, [tex]1204.82\ s = \frac{1204.82}{60}=20.08\ min[/tex]

Hence, the time taken by the ant is 1204.82 seconds or 20.08 minutes

Answer:

Explanation:

The car’s acceleration can be found by using the formula

[tex]a = \frac{v - u}{t} \\ [/tex]

where

v is the final velocity

u is the initial velocity

t is the time taken

a is the acceleration

From the question we have

[tex]a = \frac{25 - 15}{6} = \frac{10}{6} = \frac{5}{3} \\ = 1.666666...[/tex]

We have the final answer as

Hope this helps you

Hi, you've asked an incomplete question. However, I provided some explanation about the replication process that scientists do.

Explanation:

Replication in research involves carefully repeating an original experiment to see whether the same result would be arrived at as in previous research experiments.

For most scientists today, in other to avoid anything that would erroneously affect the results of the replicated experiment they usually follow the same procedures as carried by the previous researchers.

Answer: 13062.5 N

What average force is required to stop an 1100-kg car in 8.0 s if it is traveling at 95 km/h? i got the answer to be 13062.

Answer:

The answer is 13062.5 Newtons (N).

Explanation:

The mass of the car is 1100 kg.

The acceleration is 95 km/h.

Using this information, we can use Newton's 2nd Law, F=MA.

1100 kg * 95km/h = 104500 N

Because the answer wants average force, we need to divide the answer by 8 seconds, giving us 13062.5 N.

104500 N / 8 seconds = 13062.5 N (avg force).

Explanation:

A-It starts to expand. Hence ice and water of same weight has different volumes

Expansion happens to a given mass of water as it is cooled from 4°C to zero. Option A is correct.

Temperature directs to the hotness or coldness of a body. In straightforward terms,

it is the method of finding the kinetic energy of particles within an entity. Faster the motion of particles more the temperature.

Water loses density when it is cooled from 4°C to 0°C. It turns out that the temperature at which liquid water has the most significant density is 4 degrees Celsius.

It will increase in size when heated or cooled. Since most liquids shrink when they are chilled, it is rare for water to expand when cooled to lower temperatures.

As a mass of water is cooled from 4°C to zero, expansion occurs.

Hence, option A is correct.

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Answer:

t = 3 t₀

Explanation:

The formula for the power delivered by the engine can be given in terms of the change in the potential energy of the box as follows:

P = P.E/t = mgy/t

where,

P = Power delivered by the engine

m = mass of box lifted = m₀

g = acceleration due to gravity

y = vertical distance or height box covered = y₀

t = time taken = t₀

Therefore,

P = m₀gy₀/t₀

t₀ = m₀gy₀/P   -------------- equation (1)

Now, if we change the mass of box as:

m = 3m₀

y = y₀ (constant)

P = Constant

Then,

P = 3m₀gy₀/t

t = 3m₀gy₀/P

using equation (1):

t = 3 t₀

Answer:

t=3to

Explanation:

I took the quiz it is right

Answer:

p₂ / p₁ = 2 (v₁ / v₂)

Explanation:

The moment is a very useful concept, since it is one of the quantities that is conserved during shocks and explosions, for which it had to be redefined to be consistent with special relativity,

         p = m v / √[1+ (v/c)² ]

for the case of speeds much lower than the speed of light this expression is close to

         p = m v

In this exercise they indicate that the moment of the second particle is twice the moment of the first, when their velocities are small

        p₂ = 2 p₁

       p₂/p₁ = 2

in consecuense

       m v₂ = 2 m v₁

       v₂ = 2 v₁

consider particles of equal mass.

By the time their speeds increase they enter the relativistic regime

        p₂ = mv₂ /√(1 + v₂² /c²)

        p₁ = m v₁ /√(1 + v₁² / c²)

let's look for the relationship between these two moments

       p₂ / p₁ = mv₂ / mv₁   [√ (1+ v₁² / c²) /√ (1 + v₂² / c²)

from the initial statement

      p₂ / p₁ = 2 √(c² + v₁²) / (c² + v₂²)

we take c from the root

      p₂ / p₁ = 2 √ [(1+ v₁²) / (1 + v₂²)]

this is the exact result, to have an approximate shape suppose that the velocities are much greater than 1

      p₂ / p₁ = 2 √ [v₁² / v₂²] = 2 √ [(v₁ / v₂)²]

      p₂ / p₁ = 2 (v₁ / v₂)

we see the value of the moment depends on the speed of the particles

Answer: Option C) -mv / M is the correct answer

Explanation:

given that;

A rifle of mass M is initially at rest but free to recoil

velocity = v

using conversation of moment

pi = pf

i.e initial moment = final moment

But initial moment was zero (0) since everything  was rest but free to recoil

so

pi = pf

0 = mv + MV

V is the recoil velocity of the rifle

MV = -mv

V = -mv / M

Therefore Option C) -mv / M is the correct answer