All categories

3 years ago

Please help me I need these extra credit points plz plz plz

Physics

2 answers:

KengaRu [80]3 years ago

6 0

Answer:

2 half lives have passed, the rock layer is 4,000 years old

Explanation:

It takes 2,000 years for half of the 400 atoms to decay which leaves you with 200 atoms. It then takes another 2,000 years for half of the 200 atoms to decay with leaves you with 100 atoms after a total of 4,000 years and 2 half lives.

VashaNatasha [74]3 years ago

5 0

Two half lives so it is 4000 years old

You might be interested in

Which feature of the sun appears in cycles of about 11 years?

goldfiish [28.3K]

The Sun's magnetic field goes through a cycle, called the solar cycle. Every 11 years or so, the Sun's magnetic field completely flips. This means that the Sun's north and south poles switch places. Then it takes about another 11 years for the Sun's north and south poles to flip back again.

8 0

3 years ago

A bulb pile is driven to the ground with a 2.5 ton hammer. The drop height is 22 ft and the volume in last batch driven is 4 cu

Stels [109]

Answer:

159.1 ton

Explanation:

The solution is shown in the attached file

Download docx

5 0

3 years ago

Read 2 more answers

A stone is thrown vertically upwards with an initial velocity of 20m/sec. Find the maximum height ot reaches and the time taken

MAXImum [283]

Answer:

The height reached is 20m, The time taken to reach 20m is 2 seconds

Explanation:

Observing the equations of motion we can see that the following equation will be most helpful for this question.

$v^{2} = u^{2} + 2as$

We are given initial velocity, u

We know that the stone will stop at its maximum height, so final velocity, v

Acceleration, a

And we are looking for the displacement (height reached), s

Substitute the values we are given into the equation

$0^{2} = 20^{2} + 2(10)s$

Rearrange for s

$0^{2} -20^{2} =20s$

$-400=20s$

$\frac{-400}{20} =s$

s = -20 (The negative is just showing direction, it can be ignored for now)

The height reached is 20m

Use a different equation to find the time taken

$s = vt - \frac{1}{2} at^{2}$

Substitute in the values we have

$-20=(0)t - \frac{1}{2} (10)t^{2}$

Rearrange for t

$-20 =0 -5 t^{2}$

$\frac{-20}{-5} =t^{2}$

$4 = t^{2}$

t = 2s

The time taken to reach 20m is 2 seconds

4 0

3 years ago

In example 18. 4 of the text, the deflection angle of the laser beam as it exits the prism is 22. 6º. If the prism had been made

Marrrta [24]

The deflection angle is 37.29º if the prism was made of polystyrene plastic.

What is a laser beam?

Laser beam is a light beam propagating dominantly in one direction.

It is a beam of radiation produced from a laser.

Here given that,

refraction index of glass, n1= 1.52

refraction index of polystyrene plastic, n2 = 1.59

deflection angle, B = 22.6º

For the second surface,

B = 45º - 22.6º

B = 22.40º

Now from the formula of Snell's law:

n1 sinФ = n2 sin B

sin B / sinФ = n1 / n2

sinФ = (sin 22.40º) * ( 1/ 1.59)

Ф = 37.29º

Hence,

The deflection angle is 37.29º if the prism was made of polystyrene plastic.

Learn more about laser beam here:

<u>brainly.com/question/4218151</u>

#SPJ4

3 0

2 years ago

a positively charged ion, due to a cosmic ray, is headed through earth's atmosphere toward the center of Earth. Due to Earth's m

Ganezh [65]

Answer:

East direction

Explanation:

Given that

Charge on the particle is positive.

Moving towards the center of earth .

We know that N(north ) pole in magnetic fields work as source of magnetic lines and S(South ) pole works and sink for magnetic lines.

Therefore due to the earth magnetic fields , the positive ions will deflect towards East direction.

Thus the answer will be East direction.

4 0

3 years ago