4. Two scientists are experimenting with pure samples of isotope X, a highly radioactive substance. The first scientist has a sample with a mass of 20 grams. He
measures a half-life of 232 seconds. The second scientist has a sample of the same substance with a mass of 80 grams. What is the half-life that she is most likely
to measure?
A. 58 seconds
B.232 seconds
C.464 seconds
D. 928 seconds

Answer:

Wave model

Explanation:

Answer:

The answer would be a wave model

Explanation:

Answer:

A. Fusion

Explanation:

Because of the costs involved in maintaining high temperatures and pressure, nuclear fusion method for generating electrical energy.

Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles with the release of energy.

The energy realeased in the process is known as nuclear energy which can be converted into electricity.

The downside of this method of electricity generation is the equipment that will accomodate the high temperature process.

Thus, because of the costs involved in maintaining high temperatures and pressure, nuclear fusion method for generating electrical energy.

Learn more about nuclear fusion here: https://brainly.com/question/17870368

#SP J5

Answer:

The force ratio of a machine is 5 and it velocity ratio is 5 means that the load moved is five times the effort applied and the distance moved by the effort is five times the distance moved by the load at the same time interval.

Explanation:

Answer:

velocity is the rate of change of distance moved with a time in a specific direction. While speed is the rate if distance with time in no specific direction

Answer:

when an object move from its place is called an mation

Answer:

45 meters

Explanation:

20 min = 15 meters

So if 20 x 3 = 60

you have to do 3 x 15 !

- which equals to 45 <3

- mark me brainlest pls .

Answer:

it's D

Explanation:

its on edge

Answer:

the comparison of known quantity to unknown quantity or standard guantity is called measurment

Answer:

A

Explanation:

to simplify let's make it apart the denominator into three part

[tex] \frac{ {3xy}^{2} }{ {x}^{2} {y}^{2} } - \frac{ {8x}^{2} y}{ {x}^{2} {y}^{2} } + \frac{ {5x}^{2} {y}^{2} }{ {x}^{2} {y}^{2} } [/tex]

now let's simplify

[tex] \frac{3}{x} - \frac{8}{y} + 5[/tex]

so the answer is A

hope it helps

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Answer:

c glass

Explanation:

beacause glass is transparent and it would be easier to for refraction

Answer:

1 atom of oxygen

2 atoms of hydrogen in each molecule

Each water molecule contains 3 atoms making the H2O formula

Answer:

Firstly they are, by design, easy to use in most scientific and engineering calculations; you only ever have to consider multiples of 10. If I’m given a measurement of 3.4 kilometres, I can instantly see that it’s 3′400 metres, or 0.0034 Megametres, or 3′400′000 millimetres. It’s not even necessary to use arithmetic, I just have to remember the definitions of the prefixes (“kilo” is a thousand, “megametre” is a million, “milli” is a thousandth) and shift the decimal point across to the left or the right. This is especially useful when we’re considering areas, speeds, energies, or other things that have multiple units; for instance,

1 metre^2 = (1000millimetre)^2 = 1000000 mm^2.

If we were to do an equivalent conversion in Imperial, we would have

1 mile^2 = (1760 yards)^2

and we immediately have to figure out what the square of 1760 is! However, the fact that SI is based on multiples of 10 has the downside that we can’t consider division by 3, 4, 8, or 12 very easily.

Secondly they are (mostly) defined in terms of things that are (or, that we believe to be) fundamental constants. The second is defined by a certain kind of radiation that comes from a caesium atom. The metre is defined in terms of the second and the speed of light. The kelvin is defined in terms of the triple point of water. The mole is the number of atoms in 12 grams of carbon-12. The candela is defined in terms of the light intensity you get from a very specific light source. The ampere is defined using the Lorentz force between two wires. The only exception is the kilogram, which is still defined by the mass of a very specific lump of metal in a vault in France (we’re still working on a good definition for that one).

Thirdly, most of the Imperial and US customary units are defined in terms of SI. Even if you’re not personally using SI, you are probably using equipment that was designed using SI.

Answer:

Also, you could do this for the groups:

Group 1- creatures with scales

Group 2- creatures with fur

Group 3- creatures with feathers

For 4 groups you could possible do:

Group 1- no legs

Group 2- 2 legs with wings

Group 3- 2 legs without wings

Group 4- 4 legs

Answer:

D.) Nuclear fusion begins under high pressure

Explanation:

Answer:

The second step of the scientific method is the question being researched, the hypothesis. ... This hypothesis includes the explanation for the observation, it can be tested, and new conclusions may be reached. The third step of the scientific method is the experiment.

Explanation:

Answer:

The second step of the scientific method is the question being researched, the hypothesis. This hypothesis includes the explanation for the observation, it can be tested, and new conclusions may be reached. The third step of the scientific method is the experiment.

Explanation:

Answer:

true.

Explanation:

Answer:

Instantaneous speed

Explanation:

Usually the speed measuring guns are used to measure the speed at a certain instant, so the measured speed is instantaneous.

The average speed is determined by the expression final distance minus initial distance divided by time

[tex]v_{aver} =\frac{x_{f}- x_{i}}{t}[/tex]

The instantaneous speed is determined in the same way as the average, but with the exception that the travel displacements are shorter (very close one each other).

Explanation:

[tex]p1 \times v1 = p2 \times v2 [/tex]

[tex]p1 = initial \: pressure \\ v1 = initial \: volume \\ p2 = final \: pressure \\ v2 = final \: volume[/tex]

You're looking for p2. So, divide both sides by v2...

[tex] \frac{p1 \times v1}{v2} = p2[/tex]

volume of a cylinder is

[tex]h \times \pi \: \times {r}^{2} [/tex]

let's assume r = 1

[tex] \frac{p1 \times (20cm \times \pi)}{(60cm \times \pi)} = p2[/tex]

the Pi's cancel out, the 20/60 can be reduced to 1/3.

So you end up with

[tex]p1 \times \frac{1}{3} = p2[/tex]

or as the book shows....

[tex] \frac{1}{3} p[/tex]

Answer:

Magnitude = 3.64 × [tex]10^6[/tex]  

စ = 43.9°

Explanation:

given data

ship to travel = 1.7 × [tex]10^6[/tex]    kilometers

turn = 70°

travel an additional = 2.7 × [tex]10^6[/tex]   kilometers

solution

we will consider here

Px = 1.7 × [tex]10^6[/tex]  

Py = 0

Qx =2.7 × [tex]10^6[/tex]  cos(70)

Qy= 2.7 × [tex]10^6[/tex]  sin(70)

so that

Hx = Px + Qx    ............1

Hx = 2.62 × [tex]10^6[/tex]  

and

Hy = Py + Qy      ..........2

Hy = 2.53 × [tex]10^6[/tex]  

so Magnitude = [tex]\sqrt{((2.62 \times 10^6 )^2+(2.53 \times 10^6)^2)}[/tex]

Magnitude = 3.64 ×  

so direction  will be

tan စ = Hy ÷ Hx    ......................3

tan စ  = [tex]\frac{2.53}{2.62}[/tex]

tan စ  = 0.9656

စ = 43.9°

Answer:

14 m/s^2

Explanation:

Use the formula to get the velocities at 2, and 5 seconds.

Then use the average acceleration formula.

Answer: A

Explanation:

As long as the net force of the multiple forces is zero there will be no acceleration.

All periodic motions are not circular bcox they aren't similar to each other as u know the motion repeats the periodic table and also repeats itself of the tym perform the motion of the periodic...

Answer:

t is usually seen that all circular motions are usually periodic

Explanation:

but all periodic motions are not circular

this can be proved by an example for example when vehicles runs in uniform speed of motion then its speed is called periodic motion

where is his speed might not be called circular motion

if my answer is correct please mark my answer as brainliest

Answer:

Kindly check explanation

Explanation:

Given the following :

Distance between Ranjan and Gomez house = 9km

Start time = 6'o clock

Time he arrived at Gomes house = 7'o clock

Time used for chatting during this period = 5 minutes

Distance covered in 40minutes = 6km

Time spend for second part of the journey = (60 - (40 + 5))minutes = 15 minutes = 15/60 = 0.25 hoir

Distance covered during second part of journey = 9 - 6 = 3 km

Speed = distance / time

Speed = 3km / 0.25 hr = 12km/hr

Average speed for entire journey :

First part :

Speed = distance / time

Time = 40 minutes = (40/60) = 0.667 hour

Speed = 6km / 0.667 hour = 9km / hr

Average speed :

(First part + second part) / 2

(9km/hr + 12km/hr) / 2 = 21km/hr / 2 = 10.5 km/hr

= 10.5km/hr

Answer:

A heterogenous mixture.

Explanation:

If you added sand to your coffee, the kind of mixture your coffee would now

be is a heterogenous mixture.

A heterogenous mixture can be defined as any mixture which has a different or non-uniform composition and properties throughout any given sample of the mixture. This ultimately implies that, the constituents of a heterogenous mixture always remain separate in the sample and as such comprises of two or more phases.

Hence, a mixture of sand and coffee is simply a heterogenous mixture and can easily be separated into their various components.

Answer:

The answer is D. They are a mass.

Answer:

“they have mass” because if they don’t have mass they can’t exert force even if they have speed if they have no mass they can’t do anything or exert force

Explanation:

Answer:

[tex]a=2\ m/s^2[/tex]

Explanation:

Given that,

Initial velocity, u = 44 m/s

Final velocity, v = 66 m/s

Time, t = 11 s

Acceleration = rate of change of velocity

[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{66-44}{11}\\\\a=2\ m/s^2[/tex]

So, the acceleration of the car is [tex]2\ m/s^2[/tex].

Answer:

The water required to pump all the water to a platform 2 feet above the top of the pool is  is 6061310.32 foot-pound.

Explanation:

Given that,

Radius = 21 feet

Height = 10 feet

Weighing = 62.5 pounds/cubic

Work = 4329507.37572

Height = 2 feet

Let's look at a horizontal slice of water at a height of h from bottom of pool

We need to calculate the area of slice

Using formula of area

[tex]A=\pi r^2[/tex]

Put the value into the formula

[tex]A=\pi\times21^2[/tex]

[tex]A=441\pi\ feet^2[/tex]

Thickness of slice [tex]t=\Delta h\ ft[/tex]

The volume is,

[tex]V=(441\pi\times\Delta h)\ ft^3[/tex]

We need to calculate the force

Using formula of force

[tex]F=W\times V[/tex]

Where, W = water weight

V = volume

Put the value into the formula

[tex]F=62.5\times(441\pi\times\Delta h)[/tex]

[tex]F=27562.5\pi\times\Delta h\ lbs[/tex]

We need to calculate the work done

Using formula of work done

[tex]W=F\times d[/tex]

Put the value into the formula

[tex]W=27562.5\pi\times\Delta h\times(10-h)\ ft\ lbs[/tex]

We do this by integrating from h = 0 to h = 10

We need to find the total work,

Using formula of work done

[tex]W=\int_{0}^{h}{W}[/tex]

Put the value into the formula

[tex]W=\int_{0}^{10}{27562.5\pi\\times(10-h)}dh[/tex]

[tex]W=27562.5\pi(10h-\dfrac{h^2}{2})_{0}^{10}[/tex]

[tex]W=27562.5\pi(10\times10-\dfrac{100}{2}-0)[/tex]

[tex]W=4329507.37572[/tex]

To pump 2 feet above platform, then each slice has to be lifted an extra 2 feet,

So, the total distance to lift slice is (12-h) instead of of 10-h

We need to calculate the water required to pump all the water to a platform 2 feet above the top of the pool

Using formula of work done

[tex]W=\int_{0}^{h}{W}[/tex]

Put the value into the formula

[tex]W=\int_{0}^{10}{27562.5\pi\\times(12-h)}dh[/tex]

[tex]W=27562.5\pi(12h-\dfrac{h^2}{2})_{0}^{10}[/tex]

[tex]W=27562.5\pi(12\times10-\dfrac{100}{2}-0)[/tex]

[tex]W=1929375\pi[/tex]

[tex]W=6061310.32\ foot- pound[/tex]

Hence, The water required to pump all the water to a platform 2 feet above the top of the pool is  is 6061310.32 foot-pound.