Astronomers initially had difficulty identifying the emission lines in quasar spectra at optical wavelengths because

On a nice summer day,Kim takes her niece Madison for a walk in her stroller.If they start from rest and accelerate at a rate of

11111nata11111 [884]

2.5m/s

Explanation:

Given parameters:

Initial velocity = 0m/s

Acceleration = 0.5m/s²

time of travel = 5s

Solution:

Final velocity = ?

Solution:

Acceleration can be defined as the change in velocity with time:

Acceleration = $\frac{Final velocity - Initial velocity}{time}$

From the equation above, the unknown is final velocity:

Final velocity - initial velocity = Acceleration x time

since initial velocity = 0

Final velocity = 0.5 x 5 = 2.5m/s

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Acceleration brainly.com/question/3820012

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6 0

2 years ago

In very cold weather, a significant mechanism for heat loss by the human body is energy expended in warming the air taken into t

Pie

Answer:

A) $Q_a=74256\ J$

B) $Q=93562560\ J$

Explanation:

Given:

temperature of air, $T_a=-19+273=254\ K$

temperature of lungs, $T_l=37+273=310\ K$

specific Heat exchanged from the lungs , $c_l=0.47\ J.kg^{-1}.K^{-1}$

specific heat of air, $c_a=1020\ J.kg^{-1}.K^{-1}$

mass of 1 L air, $m'=1.3\ kg$

breath rate, $b=21\ breath.min^{-1}$

A)

Now,

amount of heat needed to warm the air of lungs to the body temperature:

$Q_a=m'.c_a.\Delta T$

$Q_a=1.3\times1020\times (310-254)$

$Q_a=74256\ J$

B)

Amount of heat lost per hour:

No. of breaths per hour:

$B=b.60$

$B=21\times 60$

$B=1260$

Now the total loss of energy in 1 hr.:

$Q=Q_a.B$

$Q=74256\times 1260$

$Q=93562560\ J$

7 0

2 years ago

The howler monkey is the loudest land animal and, under some circumstances, can be heard up to a distance of 8.9 km. Assume the

exis [7]

Answer:

113.7

Explanation:

maximum distance (s) = 8.9 km

reference intensity (I0) = 1 x 10^{-12} W/m^{2}

power of a juvenile howler monkey (p) = 63 x 10^{-6} W

distance (r) = 210 m

intensity (I) = power/area

where we assume the area of a sphere due to the uniformity of the output in all directions

area = 4π $r^{2}$ = 4π x $210^{2}$ = 554,176.9 m^{2}

intensity (I) = $\frac{63 x 10^{-6} }{554,176.9} = 113.7 x 10^{-12}$

therefore the desired ratio I/I0 = $\frac{113.7 x 10^{-12}}{1 x 10^{-12}}$ = 113.7

7 0

2 years ago

1. Use Coulomb’s Law (equation below) to calculate the approximate force felt by an electron at point A in the schematic below.

Amiraneli [1.4K]

Answer:

Explanation:

From the data it appears that A is the middle point between two charges.

First of all we shall calculate the field at point A .

Field due to charge -Q ( 6e⁻ ) at A

= 9 x 10⁹ x 6 x 1.6 x 10⁻¹⁹ / (2.5)² x 10⁻⁴

= 13.82 x 10⁻⁶ N/C

Its direction will be towards Q⁻

Same field will be produced by Q⁺ charge . The direction will be away

from Q⁺ towards Q⁻ .

We shall add the field to get the resultant field .

= 2 x 13.82 x 10⁻⁶

= 27.64 x 10⁻⁶ N/C

Force on electron put at A

= charge x field

= 1.6 x 10⁻¹⁹ x 27.64 x 10⁻⁶

= 44.22 x 10⁻²⁵ N

8 0

2 years ago

A small cylinder rests on a circular turntable that is rotating clockwise at a constant speed. Which set of vectors gives the di

I am Lyosha [343]

The question is missing the diagram. Also, the choices must have pictorial representation. So, I have attached the missing diagram and the pictorial representation of the vectors.

Answer:

The correct representation is attached below. Force and acceleration will be towards the center of rotation while the velocity will be along the tangent to the circular motion. Option (D).

Explanation:

From the figure, we can conclude the following points:

1. The cylinder is under a uniform circular motion as the circular table is moving at constant speed.

2. For a circular motion, velocity acts along the tangent to the circular path.

3. For a circular motion, centripetal force acts on the body that causes it move around a circular path.

4 The direction of the centripetal force is radially inward towards the center of rotation.

5. The centripetal force causes a centripetal acceleration acting on the body.

6. From Newton's second law, the net acceleration of a body is in the same direction as that of the net force acting on it. So, centripetal acceleration also acts in the radially inward direction.

Therefore, from the above conclusions, it is clear that velocity will act in the horizontal direction at the given instance of time and force and acceleration will act vertically down for the given instance.

This is shown in the picture below. The option (D).

4 0

2 years ago