I have no idea so i'm screwed please help me
Beryllium-11 has a half-life of 13.81 s. What percent of the initial sample will remain aft er 30.0 s?

Answer:

We wouldn't have our moon and sun. The earth will be colder and darker

Explanation:

Answer:

mars will become habitabe

Explanation:

true fact and every planet will become close to sun

top ( 25 m ) | 75000 j | 0 j | 75000 j

-------------------|---------------|------------|-------------

bottom ( 0 ) | 0 j | 75000j | 75000 j

-------------------|---------------|------------|-------------

h d ( 12.5 m ) | 37500 j | 37500j | 75000 j

-------------------|---------------|------------|-------------

f d ( 5 m ) | 15000 j | 60000j | 75000 j

-------------------|---------------|------------|-------------

Answer:Chemical energy

Explanation:, Energy stored in the bonds of chemical compounds. Chemical energy may be released during a chemical reaction, often in the form of heat; such reactions are called exothermic.

Answer:

Hope this helps

Explanation:

Chemical energy, Energy stored in the bonds of chemical compounds Chemical energy may be released during a chemical reaction, often in the form of heat such reactions are exothermic. The chemical energy in food us converted by the body into mechanical energy and heat .

4 N to right

( the third option )

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

Answer:

1. [tex]h = 244.8 m[/tex]    

2. [tex]x = 564.8 m[/tex]  

Explanation:

1. La altura máxima se puede calcular usando la siguiente ecuación:

[tex] v_{f}^{2} = v_{0}^{2} - 2gh [/tex]     (1)                        

Where:

[tex]v_{f_{y}}[/tex]: es la velocidad final = 0 (en la altura máxima)  

[tex]v_{0_{y}}[/tex]: es la velocidad inicial horizontal en "y"

g: es la gravedad = 9.81 m/s²          

h: es la altura máxima =?

La velocidad incial en "y" se puede calcular de la siguiente manera:

[tex] tan(\theta) = \frac{v_{0_{y}}}{v_{0_{x}}} [/tex]

[tex] v_{0_{y}} = tan(60)*40 m/s = 69.3 m/s [/tex]                    

Resolviendo la ecuación (1) para "h" tenemos:

[tex]h = \frac{v_{0_{y}}^{2}}{2g} = \frac{(69.3 m/s)^{2}}{2*9.81 m/s^{2}} = 244.8 m[/tex]          

2. Para calcular el alcance horizontal podemos usar la ecuación:

[tex]x = v_{x}*t[/tex]

Primero debemos encontrar el tiempo cuando la altura es máxima ([tex]v_{f_{y}}[/tex] = 0).

[tex] v_{f_{y}} = v_{0_{y}} - gt [/tex]    

[tex] t = \frac{v_{0_{y}}}{g} = \frac{69.3 m/s}{9.81 m/s^{2}} = 7.06 s [/tex]      

Ahora, como el tiempo de subida es el mismo que el tiempo de bajada, el tiempo máximo es:

[tex] t_{m} = 2*7.06 s = 14.12 s [/tex]          

Finalmente, el alcance horizontal es:

[tex]x = 40 m/s*14.12 s = 564.8 m[/tex]                                                            

Espero que te sea de utilidad!

Explanation:

A wave having a frequency of 200 Hz means that 200 such waves pass through a point per second.

Answer:

the correct answer is B

Explanation:

The law of reflection states that the angles of incidence and reflection on a surface are the same, the two rays and the normal are in the same part of the surface.

In this exercise indicate that the angle between the incident and reflected ray is 10, therefore the angle with respect to the normal that is a vertical line at the point of contact of the ray must be 5

Consequently the correct answer is B

Answer:

chonks of rock will hit the earth and if one astoroid is big enough it can distroy all liofe on earth

Explanation:

Answer:

If we nuke the moon, it won't have any sound and will quickly be stopped from travelling any further than the place we nuked it. If some parts of the moon crack and break, it will be forced down on us (like an asteroid).

Many possibilities can happen but I'm just listing one of them.

Answer:

a.  9.99625 cm b. 68 °C

Explanation:

(a) What is the length of the rod at the freezing point of water (0 0C)?

Before we find the length of the rod, we need to find the coefficient of linear expansion, α = (L - L₀)/[L₀(T - T₀)] where L₀ = length of rod at temperature T₀ = 10.0 cm, T₀ = 20 °C, L = length of rod at temperature T = 10.015 cm and T = 100 °C

Substituting the values of the variables into the equation, we have

α = (L - L₀)/[L₀(T - T₀)]

α = (10.015 cm - 10.0 cm)/[10.0 cm(100 °C - 20 °C)]

α = 0.015 cm/[10.0 cm × 80 °C]

α = 0.015 cm/[800.0 cm °C]

α = 0.00001875 /°C

We now find the length L₁ at T₁ = 0 °C from

L₁ = L₀(1 + α(T₁ - T₀))

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

L₁ = L₀(1 + α(T₁ - T₀))

L₁ = 10.0 cm[1 +  0.00001875 /°C(0° C - 20 °C)]

L₁ = 10.0 cm[1 +  0.00001875 /°C × -20° C]

L₁ = 10.0 cm[1 - 0.000375]

L₁ = 10.0 cm[0.999625]

L₁ = 9.99625 cm

(b) What is the temperature if the length of the rod is 10.009 cm?

With length L₃ = 10.009 cm at temperature T₃, using

L₃ = L₀(1 + α(T₃ - T₀))

making T₃ subject of the formula, we have

L₃/L₀ = 1 + α(T₃ - T₀)

L₃/L₀ - 1 = α(T₃ - T₀)

T₃ - T₀ = (L₃/L₀ - 1)/α

T₃ = T₀ + (L₃/L₀ - 1)/α

substituting the values of the variables into the equation, we have

T₃ = 20 °C + (10.009 cm/10.0 cm - 1)/0.00001875 /°C

T₃ = 20 °C + (1.0009 - 1)/0.00001875 /°C

T₃ = 20 °C + 0.0009/0.00001875 /°C

T₃ = 20 °C + 48 °C

T₃ = 68 °C

Answer:

Impulse = 50,000 J

Explanation:

Given: force = 100,000 kg ms^2 or N; time = 0.5 s

Unknown: impulse = ?

Equation: impulse = (force)(time)

Substitute: impulse = (100,000 kg ms^2 or N)(0.5 s)

Solution: impusle = 50,000 kg ms^2 or J

Answer:

Solution given:

strength of electric field [E]:?

distance[d]:0.2m

charge[Q]=[tex]1.56×10^{-6} C[/tex]

we have

E =K [tex] \frac{Q}{r²}[/tex]

E=[tex]9×10^{9} C[/tex][tex] \frac{1.56×10^-6 C}{0.2²} [/tex]

E=[tex] 3.51×10^{5}[/tex]V/m

strength of electric field : [tex] 3.51×10^{5}[/tex]V/m

Answer:

The question above would be written again but this time with options attached to it for comprehension sake:

Which of the following best describes the formation of surf?

A.  Waves energy, rebounding from its impact with shore, crashes into oncoming waves, causing them to break.

B. Entering shallow water forces wave energy upward, making the wave crest unstable and causing it to break.

C. A wave encountering shallow water begins to slow at its bottom, while the top of the wave continues at its previous speed. This causes the wave to break.

D. As waves enter shallow water, the distance between wave crests (wavelength) shortens, increasing the tendency to break.

The correct answer is option C (A wave encountering shallow water begins to slow at its bottom, while the top of the wave continues at its previous speed. This causes the wave to break).

Explanation:

Surf could mean crashing waves or breaking waves. Generally, the wave speed is constant in the same medium, however, the wave speed decreases as it enters shallow water which is largely due to the water depth which is relatively small, especially when it encounters the bottom of the shallow water. While the top of the wave overtakes the bottom of the wave, making sure the top of the wave continues at its previous speed.

Answer:

A) terminal moraines

Explanation:

Moraines are the rocks and sediments deposited by moving glaciers. Terminal means the end, the furthest the glacier travels. Lateral means what's deposited along the sides of the moving glacier.

Answer:

The magnetic field will help to create an electromagnetic radiation which will prevent the charged particle from moving in a constant direction in a straight path.

Explanation: A magnetic field is an area around a particle where magnetic energy is felt or experienced, this ensures that all the charged particle within the magnetic field will be influenced by magnet.

In the highlighted situation, the magnetic field will help to ensure that an electromagnetic radiation is created to synchrotron radiation occurs effectively.

Answer:

Explanation:

F = ma. For us, this looks like

60 = 30a and

a = 2 m/s/s

If the force goes up to, say, 90, then

90 = 30a and

a = 3...if the force goes up, the acceleration also goes up.

If the mass goes up to say, 60, and the force stays the same, then

60 = 60a and

a = 1...if the mass goes up, the acceleration goes down.

Answer:

271 K

Explanation:

Answer:

The temperature of Nitrogen is 270.85 K.

Explanation:

A gas that follows Boyle's law , Charle's law and law of pressure , is called perfect gas.

Given data;

[tex]P =101.3 KPa , V = 0.08 m^{3} , \\ n = 3.6 mol , R = 8.31\\T = ?[/tex]

By the formula,

P.V = n .R.T

On putting values

[tex]1.013[/tex] x [tex]10^{5}[/tex] x [tex]0.08[/tex] = [tex]3.6[/tex] x [tex]8.31[/tex] x [tex]T[/tex]

So [tex]T =\frac{1.013*10^{5} * 0.08}{3.6 * 8.31}[/tex]

 [tex]T =\frac{8104}{29.92}[/tex]

[tex]T = 270.85 K[/tex]

Hence the temperature of Nitrogen is 270.85 K

For more details also read -

https://brainly.com/question/12744632?referrer=searchResults

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Answer:

0.0469

Explanation:

v=1.50

r=32.0

i=?

equation

i=v/r

i=1.50/32.0

i=0.046875

round to 3 sig figs

i=0.0469

Answer:

.0469

Explanation:

acellus

Answer:

Option D

Explanation:

The options for the question are

a) How do galaxies rotate?

b) What is the weather on Neptune?

c) What is the core of Saturn made of?

d) What other solar systems have planets?

Solution

The Hubble space telescope was designed and integrated into the extraterrestrial system in order to capture information about the surrounding universe. If the  Keck Observatory has a better observation capacity than the Hubble space telescope then the scientist would be interested to know the surrounding planets in the solar system.

Hence, option D is correct

Answer:

b-gravity

Explanation:

newton discovered the general concept of gravity and how it effects earth. he didn't discord it so much as the concept of it.

Newton discovered gravity.

Hope this helps; please mark me brainliest!

Have a wonderful day!

Answer:

No.

Explanation:

A feather is less dense and thus less force exerted while a rock is very dense thus exerting more force .

Answer:

The given potential energy of the spring is expressed as follows;

ΔUsp = -(WB + WW)

Where;

WB = Th work done by the spring on the block to which it is attached

WW = The work done by the spring on the wall

We recall that work done, W = Force applied × Distance moved in the direction of the force

The work done by the spring on the block, WB = The spring force × The distance the block moves

The work done by the spring on the wall, WW = The spring force × The distance the wall moves

However, given that the wall does not move, we have;

The distance the wall moves = 0

∴ The work done by the spring on the wall, WW = The spring force × 0 = 0 J

Therefore, WW = 0 J, and the spring does not do work on the wall, and WW can be ignored in the next subsequent) steps

Explanation:

Answer:

Average speed = 53.33 km/h

Explanation:

Below is the calculation for the average speed:

Given the average speed of for first 40 km = 80km/h

Time taken to cover the first 40 km = Total Distance / average speed

Time taken to cover the first 40 km = 40 / 80 = 0.5 hours

Given the average speed of for next 40 km = 40km/h

Time taken to cover the next 40 km = Total Distance / average speed

Time taken to cover the next 40 km = 40 / 40 = 1 hours

Now the average speed of the tuck to cover total distance:

Average speed = Total distance / Total time

Average speed = (40 + 40) / (0.5 + 1)

Average speed = 53.33 km/h

Answer:

k = 933.88 N/m

Explanation:

Given that,

The mass of a load, m = 8.1 kg

The displacement in the spring, x = 8.5 cm

We need to find the force constant of the spring. We know that Hooke's law is given by :

F = -kx

Also,

F = mg (Force due to its weight)

So,

[tex]k=\dfrac{mg}{x}\\\\k=\dfrac{8.1\times 9.8}{0.085}\\\\k=933.88\ N/m[/tex]

So, the force constant of the spring is equal to 933.88 N/m.

Answer:

[tex]31.6\:\mathrm{m/s}[/tex]

Explanation:

The elastic potential energy of a spring is given by [tex]Us=\frac{1}{2}kx^2[/tex], where [tex]k[/tex] is the spring constant of the spring and [tex]x[/tex] is displacement from point of equilibrium.

When released, this potential energy will be converted into kinetic energy. Kinetic energy is given by [tex]KE=\frac{1}{2}mv^2[/tex], where [tex]m[/tex] is the mass of the object and [tex]v[/tex] is the object's velocity.

Thus, we have:

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

Substituting given values, we get:

[tex]\frac{1}{2}\cdot 50\cdot 0.2^2=\frac{1}{2}\cdot 0.002\cdot v^2,\\v^2=\frac{50\cdot 0.2^2}{0.002},\\v^2=1000,\\v\approx \boxed{31.6\:\mathrm{m/s}}[/tex]

Work done = Froce × distance

Now, keeping this formula in mimd, we can find the distance as follows;

= 1.56 = 300 × distance

= 1.56/300 = distance

= 156/30000 = distance

= 0.0052 m = distance

Lets convert it into cm so that you don't get troubled seeing it :)

= 1 m = 100cm

= 0.0052 × 100

= 0.52 cm

Answer:

I'm pretty sure its C

Explanation:

Answer:

B - Person A's chair rolls backwards.

Explanation:

This can be seen simply through the Conservation of Momentum. When the ball is thrown to be, the ball's momentum(+m) is transfererd to B, so B's chair moves forward(think about it - it makes sense, doesn't it?), meaning A's chair moves backwards.

So, B.

EXTRA TIP: Try drawing a diagram to help you!