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bearhunter [10]

3 years ago

12

The Danish scientist Niels Bohr proposed a model of the atom that is not totally accurate today but still contains components th

at are useful for today's students.
Bohr's model is sometimes called the __________ model because it resembles a mini-solar system.
A. universal
B. planetary
C. atomic
D. nuclear

1 answer:

blagie [28]3 years ago

7 0

Answer:

Option B

Planetary

Explanation:

In 1913, Niels Bohr proposed a model to explain the stability of orbits around the nucleus. Niels believed that light is emitted by an electron when the electron's energy changes. Bohr Atomic Model is sometimes called planetary model because it resembles a mini-solar system.

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A company intends to market a new product and it estimates that there is a 20% chance that it will be first in the market

Stells [14]

The EMV - Ending Market Value is given as:
$2,400,000.

<h3>How is the EMV Arrived At?</h3>

The EMV is given as:

BMV x (i + r); Where

BMV is the Beginning Market Value; and

r is the interest rateor percentage given.

Hence the EMV = 2,000,000 x ( 1 + 20%)

= 2,000,000 x 1.2

= $ 2, 400,000.

It is to be noted that the BMV is the Beginning Market Value which is the value of an investment at the start of the business period.

Learn more about Market Value at:

brainly.com/question/1350233

4 0

2 years ago

The car travels around the portion of a circular track having a radius of r = 500 ft such that when it is at point A it has a ve

stellarik [79]

Answer:

Explanation:

Given

velocity at A is $v=4\ ft/s$

For $r=500\ ft$

velocity is increasing at $\dot{v}=0.004t\ ft/s^2$

Tangential acceleration is given by

$a_t=\frac{\mathrm{d} v}{\mathrm{d} t}$

$a_t=0.004t=\frac{\mathrm{d} v}{\mathrm{d} t}$

$\int 0.004tdt=\int dv$

$\int dv=\int 0.004tdt$

$v=0.002t^2+c$

at $t=0\ v=4\ ft/s$

$4=0.002\cdot 0+c$

$c=4\ ft/s$

thus $v=0.002t^2+4$

Velocity in terms of Displacement is given by

$v=\frac{\mathrm{d} s}{\mathrm{d} t}$

$\Rightarrow \int ds=\int \left ( 0.002t^2+4\right )dt$

$\Rightarrow s=\frac{0.002t^3}{3}+4t$

When car has traveled $\frac{3}{4}$ th of distance i.e.

$s=\frac{3}{4}\times (2\pi r)=\frac{3\pi r}{2}$

$s=750\pi$

$750\pi =\frac{0.002t^3}{3}+4t$

$\Rightarrow \frac{0.002t^3}{3}+4t-2356.5=0$

on solving we get $t=139.23\ s$

Thus velocity at $t=139.23\ s$

$v=42.76\ s$

(b)Acceleration when car has traveled three-fourth the way of track

normal acceleration $a_n=\frac{v^2}{r}=\frac{(42.76)^2}{500}$

$a_n=3.658\ m/s^2$

Tangential acceleration $a_t at t=139.23\ s$

$a_t=0.556\ m/s^2$

Net acceleration $a_t=\sqrt{(a_n)^2+(a_t)^2}$

$a_n=\sqrt{(3.658)^2+(0.556)^2}$

$a_n=3.7\ m/s^2$

8 0

3 years ago

An approach to a signalized intersection has a saturation flow rate of 1800 veh/h. At the beginning of an effective red, there a

Tcecarenko [31]

Answer: The total vehicle delay is

39sec/veh

Explanation: we shall define only the values that are important to this question, so that the solution will be very clear for your understanding.

Effective red time (r) = 25sec

Arrival rate (A) = 900veh/h = 0.25veh/sec

Departure rate (D) = 1800veh/h = 0.5veh/sec

STEP1: FIND THE TRAFFIC INTENSITY (p)

p = A ÷ D

p = 0.25 ÷ 0.5 = 0.5

STEP 2: FIND THE TOTAL VEHICLE DELAY AFTER ONE CYCLE

The total vehicle delay is how long it will take a vehicle to wait on the queue, before passing.

Dt = (A × r^2) ÷ 2(1 - p)

Dt = (0.25 × 25^2) ÷ 2(1 - 0.5)

Dt = 156.25 ÷ 4 = 39.0625

Therefore the total vehicle delay after one cycle is;

Dt = 39

4 0

2 years ago

Rosalind franklin<br> What was she famous for

liq [111]

Answer:

She was known for her work on X-ray diffraction images of DNA, which led to the discovery of the DNA double helix for which Francis Crick, James Watson, and Maurice Wilkins shared the Nobel Prize in Physiology or Medicine in 1962.

Explanation:

5 0

3 years ago

What are the BENEFITS and RISKS of using automobiles?

Molodets [167]

Answer:

u could get hurt or it could not sence in but it easy to work with and u can just relax till u get were ur going.

Explanation:

3 0

2 years ago