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2 years ago

Active immunity is passed on from a mother to her baby.

1 answer:

3 0

True.The immune system in babies. Antibodies are passed from mother to baby through the placenta during the last three months of pregnancy.

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A mass spectrometer is being used to separate common oxygen-16 from the much rarer oxygen-18, taken from a sample of old glacial

Nataly_w [17]

Answer:

0.092 m

Explanation:

A charged moving particle immersed in a region with magnetic field follows a circular trajectory at constant speed (uniform circular motion), since the magnetic forces acts perpendicular to the direction of motion of the particle.

Since the magnetic force acts as centripetal force, we can write:

$qvB=m\frac{v^2}{r}$

where

q is the charge of the particle

v is its velocity

B is the strength of the magnetic field

m is the mass of the particle

r is the radius of the orbit

Solving the equation for r,

$r=\frac{mv}{qB}$

For the ion of oxygen-16, we have:

$m_A=2.66\cdot 10^{-26}kg$

$q_A = 1.6\cdot 10^{-19}C$ (it is singly charged)

$v_A=2.90\cdot 10^6 m/s$

$B_A=1.30 T$

So the radius of its orbit is

$r_A=\frac{m_A v_A}{q_A B_A}=\frac{(2.66\cdot 10^{-26})(2.90\cdot 10^6)}{(1.6\cdot 10^{-19})(1.30)}=0.371 m$

For the ion of oxygen-18, we have:

$m_B = \frac{18}{16}m_A = 2.99\cdot 10^{-26}kg$

$q_B = 1.6\cdot 10^{-19}C$ (it is singly charged)

$v_B=2.90\cdot 10^6 m/s$

$B_B=1.30 T$

So the radius of its orbit is

$r_B=\frac{m_B v_B}{q_B B_B}=\frac{(2.99\cdot 10^{-26})(2.90\cdot 10^6)}{(1.6\cdot 10^{-19})(1.30)}=0.417 m$

After each ion has travelled a semicircle, the separation between the two ions will be twice the difference in their radius, so:

$d=2(r_B-r_A)=2(0.417-0.371)=0.092 m$

3 0

2 years ago

What are some climate facts

aleksley [76]

The greenhouse effect is a warming effect caused by certain gases that retain heat from sunlight. Without such gases, the average surface temperature of the Earth would be below freezing, and as explained by the Encyclopedia of Environmental Science, “life, as we know it, would not exist.”

The global warming debate is centered upon whether added greenhouse gases released by human activity will overheat the Earth and cause harmful effects.

5 0

3 years ago

Now consider the statements in Part A that are inferred from models. A solar model is used to calculate interior conditions base

mafiozo [28]

Answer:

d. We can calculate it by applying Newton's version of Kepler's third law

Explanation:

The measurements of a Star like the Sun have several problems, the first one is distance, but the most important is the temperature since as we get closer all the instruments will melt. This is why all measurements must be indirect because of the effects that these variables create on nearby bodies.

Kepler's laws are deduced from Newton's law of universal gravitation, in these laws the mass of the Sun affects the orbit of the planets since it creates a force of attraction, if measured the orbit and the time it takes to travel it we can know the centripetal acceleration and with it knows the force, from where we clear the mass of the son.

Let's review the statements of the exercise

.a) False. We don't have good enough models for this calculation

.b) False. The size of the sun is very difficult to measure because it is a mass of gas, in addition the density changes strongly with depth

.c) False. The amount of light that comes out of the sun is not all the light produced and is due to quantum effects where the mass of the sun is not taken into account

.d) True. This method has been used to calculate the mass of the sun and the other planets since the variable distance and time are easily measured from Earth

Correct answer is D

6 0

2 years ago

Different kinds of electromagnetic waves are identified by their -?-

const2013 [10]

Answer:

frequency or wavelength

Explanation:

this is why the electromagnetic spectrum has a decreasing wavelength and increasing frequency

4 0

2 years ago

Which is usually greater for a pair of surfaces, the coefficient of static friction or the coefficient of sliding friction? why

lorasvet [3.4K]

Explanation :

Static friction is the frictional force between two objects that are at rest. While sliding friction is the frictional force between two objects in contact and are sliding w.r.t each other.

Static friction is usually greater than sliding friction because in static friction the contact forces is more and the interlocking between objects is tight as compared to sliding friction.

5 0

3 years ago