Do only number 4 and thank

Answer:

it is difficult

my best answer would be a. 6

hope its right!!

===========================================

Explanation:

The half-life formula is

y = A*(1/2)^(x/H)

where A is the starting amount, H is the half-life, x is the time value and y is the amount after x units of time have passed.

I'll express the x and H values in terms of millions of years. So for example, when we say H = 500, then that really refers to 500 million years.

----------

In this case, we know that,

Let's use those values to solve for x. We'll need logs to cut the exponents down from the trees.

y = A*(1/2)^(x/H)

3 = 192*(1/2)^(x/500)

3/192 = (0.5)^(x/500)

0.015625 = (0.5)^(x/500)

log(0.015625) = log( (0.5)^(x/500) )

log(0.015625) = (x/500)*log(0.5)

(x/500)*log(0.5) = log(0.015625)

x = 500*log(0.015625)/log(0.5)

x = 3,000

Keep in mind that x is in millions of years. So saying x = 3,000 means 3,000 million years. This translates to 3,000*10^6 = 3,000,000,000 = 3 billion years.

It will take about 3 billion years for the 192 atoms to decay to only 3 atoms.

The amount of half-lives this occurs is x/H = (3,000)/500 = 6

So the time span of 3 billion years is the same as 6 half-lives when each half-life is 500 million years long.

Answer:

The horizontal component of the vector ≈ -16.06

The vertical component of the vector ≈ 19.15

Explanation:

The magnitude of the vector, [tex]\left | R \right |[/tex] = 25 units

The direction of the vector, θ = 130°

Therefore, we have;

The horizontal component of the vector, Rₓ = [tex]\left | R \right |[/tex] × cos(θ)

∴ Rₓ = 25 × cos(130°) ≈ -16.06

The horizontal component of the vector, Rₓ ≈ -16.06

The vertical component of the vector, R[tex]_y[/tex] = [tex]\left | R \right |[/tex] × sin(θ)

∴  R[tex]_y[/tex] = 25 × sin(130°) ≈ 19.15

The vertical component of the vector, R[tex]_y[/tex] ≈ 19.15

(The vector, R = Rₓ + R[tex]_y[/tex]

[tex]\underset{R}{\rightarrow}[/tex] = Rₓ·i + R[tex]_y[/tex]·j

∴ [tex]\underset{R}{\rightarrow}[/tex] ≈ -16.07·i + 19.15j)

Answer:

The net force acting on the car is zero.

Explanation:

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

Mass (m) = 350 Kg

Velocity (v) = constant = 15 m/s

Net Force (F) =?

An object moving with a constant velocity is not accelerating. The acceleration of such object is zero. Thus, the net force acting on the object is also zero. This can further be explained as shown below:

Mass (m) = 350 Kg

Acceleration = 0 (since the velocity is constant)

Net Force (F) =?

Force (F) = mass (m) × Acceleration (a)

F = m × a

F = 350 × 0

F = 0

Thus, the net force acting on the car is zero.

Answer:

Cost of energy = N230.4

Explanation:

Given the following data;

Time = 8 hours

Power = 1200 W

Voltage = 240 V

Cost of energy = N24

To find the cost of running an electric laundry iron;

First of all, we would determine the energy consumption of the iron.

Energy = power * time

Energy = 1200 * 8

Energy = 9600 Watt-hour = 9.6 Kwh (1 Kilowatts is equal to 1000 watts).

Next, we find the cost of energy;

Cost of energy = 9.6 * 24

Cost of energy = N230.4

Answer:

C. Alleles

Explanation:

Our genes are responsible for our phenotype (physical traits). Alleles is the only genetic term in there.

Answer:

its not B1 or A1. must be A2 or C2

Explanation:

Answer: hey, i hope this hlps!~~~ Part of mental health is how well your mind processes and understands information and experiences. In contrast, emotional health involves your ability to manage and express the emotions that arise from what you have learned and experienced.

Explanation:

Answer:

v = 3.53x10⁻³ m/s.

Explanation:

We can find the velocity of the rock by energy conservation:

[tex] \Sigma E_{i} = \Sigma E_{f} [/tex]        

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

Where:

i is for initial and f is for final

k: is the stiffness of the rubber = 20 N/m

x: is the distance of the rubber compression = 5 mm = 0.005 m

m: is the mass of the stone = 40 kg

v: is the velocity =?

Hence, the velocity is:

[tex]v = \sqrt{\frac{kx^{2}}{m}} = \sqrt{\frac{20 N/m(0.005 m)^{2}}{40 kg}} = 3.53 \cdot 10^{-3} m/s[/tex]

Therefore, the velocity with which the stone leaves the catapult is 3.53x10⁻³ m/s.

I hope it helps you!  

Answer:

the front of the human head from the forehead to the chin and ear to ear

Explanation:

Hope this helps

Answer:

They are temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness. Together, these components describe the weather at any given time.

Answer: D

Explanation:

An elastic collision is a collision in which there is no net loss in kinetic energy in the system as a result of the collision. Both momentum and kinetic energy are conserved quantities in elastic collisions. Suppose two similar trolleys are traveling toward each other with equal speed.

Answer:

electrons i think

Explanation:

Answer:

Yes, but only if it's sunny.

Explanation:

As you know, solar panels generate energy through the sun's rays of light (better known as sunlight). Therefore, as long as the sun is shining high in the sky, the car will generate electricity and be able to function. If this vehicle was only powered by solar panels, it would not function during the night, in cloudy areas, and/or in dark places (such as parking garages or home garages).

Hope this helps!

Answer:

They break off large ice sheets found at the North and South poles.

Answer:

The answer is D

Explanation:

They break off large ice sheets found at the poles.

Answer:

1. The reason why nichrome wire is used in a heater is due to the properties of nichrome which makes it a material of choice for heating application including;

i) The cost of manufacture of nichrome is low

ii) Nichrome has both high mechanical and creep strength, and therefore is suitable for installation and use in a wide setting

iii) Nichrome has a high resistance to electron flow, making it a good electrical heating element

iv) Nichrome has a high resistance to oxidation, such that it can be reused several times as a heater

v) The high ductility of nichrome allows it to be stretched and drawn around different vessels with contents to which heat is to be supplied

2. Copper wire is not used in heaters because according to Joule's law, the heat produced from the flow of electric current, 'I', through a material having a resistance, 'R', for a time, 't', is proportional to I²·R·t, and copper has a very low resistance, 'R', to the flow of electric current, and therefore, will not produce sufficient heat required at a given current level

Explanation:

Answer:

(a) 0.71 mm

(b) 0.158 cubic cm

Explanation:

The width of one wire is the diameter of the wire.

(a) Let the diameter of each wire is d.

So, 10 d = 14.2 mm

d = 1.42 mm

radius of each wire, r = d/2 = 1.42/2 = 0.71 mm

(b) Length, L = 10 cm

The volume of the single wire is given by

[tex]V =\pi\times r^2\times h \\\\V =3.14\times 0.071^2\times 10\\\\V =0.158 cm^3[/tex]

Answer:

A

Explanation:

Answer: E- An opera singer breaks a thin glass with only the use of her high frequency voice

Explanation:

Resonance is when a person is able to evoke emotions or when a person is deep in character. It is the ability to evoke memories, images and emotions.

Examples of resonance include old pictures which has emotional attachments, feel voice of a singer etc.

Therefore, the event that is an example of resonance is an opera singer breaks a thin glass with only the use of her high frequency voice.

Answer:

The horizontal component of the vector is approximately -16.07

The vertical component of the vector is approximately 19.15

Explanation:

A vector quantity is a quantity that posses both magnitude and direction specifications

The magnitude of the given vector, R = 25 units

The direction of the vector, θ = 130°

Therefore the location of the vector, starting from the origin of the Cartesian plane, is in the second quadrant having an angle of 180° - 130° = 50° to the horizontal

Given that the x-coordinate  is negative in the second quadrant, we have;

The horizontal component of the vector, Rₓ = The x-coordinate of the vector = R×cos(θ)

∴ The horizontal component of the vector, Rₓ = 25 × cos(130°) = -25 × cos(50°) ≈ -16.07

The horizontal component of the vector, Rₓ ≈ -16.07

The vertical component of the vector, [tex]R_y[/tex] = The y-coordinate of the vector = R×sin(θ)

∴ The vertical component of the vector, [tex]R_y[/tex] = 25 × sin(130°) ≈ 19.15

The vertical component of the vector, [tex]R_y[/tex] ≈ 19.15

The vector can be resolved as R = -16.07·i + 19.15·j

So, we know that this question is about photoelectric effect.

What is photoelectric effect?

-Photoelectric effect is a phenomenon where electrons are released from a material whenever an electromagnetic radiation such as light, hits it.

-This phenomenon is first discovered by Heinrich Rudolf Hertz in 1887 whereas Albert Einstein, in 1905, resolved the conflict between the photoelectric effect and Maxwell's electromagnetic wave theory of light.

Now to your question, the intensity of light only determines the number of the electrons released, not their maximum kinetic energy because this are proportional to the light's frequency.

Also, there is no time lag detected between the entry of radiation and the emission of electrons in experiments held.

So, with letter A and C out, we can therefore conclude that the answer for this is Letter B

The correct answer is B: the number of electrons ejected per second

The Einstein photoelectric equation states that;

[tex]KE = hf - hfo[/tex]

Where

KE = kinetic energy of the ejected photo electrons

h = Plank's constant

f = frequency of incident light

fo = threshold frequency.

The kinetic energy of ejected photoelectrons depends on frequency of incident photon and not on the intensity of the incident photon.

However, the number of photoelectrons ejected per second depends on the intensity of the incident blue light.

https://brainly.com/question/9260704

Answer:

elastic collision

Explanation:

Answer:

C. Electromagnetic wave

Explanation:

Please give me brainliest

Answer:

C. electromagnetic

Explanation:

because 5g uses higher frequency radio waves a type of electromagnetic radiation which are within the spectrum considered safe.

Answer:

a. 6.5 × 10⁴ mmHg

b. 5.9 × 10⁻⁴ atm

c. 1.0 × 10⁵ Pa

d. 0.97 atm

Explanation:

Transformaremos las siguientes unidades utilizando factores de conversión.

a. 85 atm a mmHg

Usaremos el factor de conversion 1 atm = 760 mmHg.

85 atm × 760 mmHg/1 atm = 6.5 × 10⁴ mmHg

b. 60 Pa a atm

Usaremos el factor de conversion 1 atm = 101325 Pa.

60 Pa × 1 atm/101325 Pa = 5.9 × 10⁻⁴ atm

c. 780 mmHg a Pa

Usaremos el factor de conversion 760 mmHg = 101325 Pa.

780 mmHg × 101325 Pa/760 mmHg = 1.0 × 10⁵ Pa

d. 740 mmHg a atm

Usaremos el factor de conversion 1 atm = 760 mmHg.

740 mmHg × 1 atm/760 mmHg = 0.97 atm

Answer:

Explanation:

T = 2π √ (m/k)

T / 2π = √ (m/k)

T√k = 2π √m

(T√k) / 2π = √m

( (T√k) / 2π)^2 = m

m = ( (7.5√82.5) / 2π)^2

m = 117.66 Kg

Answer:

For Ryan:

[tex]at \: highest \: point : v = 0 \\ velocity = 0 \: {ms}^{ - 1} [/tex]

For the football kicked:

[tex]s = ut - \frac{1}{2} g {t}^{2} \\ for \: range : s = 0 \\ u \sin( \theta) = \frac{gt}{2} \\ t = \frac{2u \sin(\theta) }{g} \\ range(x) = ut \\ x = \frac{ {2u {}^{2} \sin(\theta) }^{} }{g} \\ \frac{50 \times 9.8}{ {2318.9}^{} } = \sin(\theta) \\ \\but \: 0 = u \sin(25) - 2 \times 9.8 \times 50 \\ u = 2318.9 \: {ms}^{ - 1} \\ \theta = 12.2 \degree[/tex]

Answer:

the highest point for the first question is 0 meters per second

the answer for question 2 is 45 degrees

Answer:

Explanation:

The formula for this is designed around the fact that momentum must be conserved:

[tex][(m_{ball1}*v_{ball1})+(m_{ball2}*v_{ball2})]_b=[(m_{ball1}+m_{ball2})v_{both}]_a[/tex]

This is because they sitck together after they collide. Filling in:

[(3*10)+(5*2)] = [3 + 5]v and

30 + 10 = 8v so

40 = 8v and

v = 5

They are both moving east at a velocity of 5 m/s since they stuck together.

Answer:

A

Explanation:

because she wants to practice science and A is the practical option.