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3 years ago

Explain how we can deduce the temperature of a star by determining its color.

1 answer:

7 0

Answer: Stars are bright and have the ability to emit lights of various wavelength. The color of a star plays a significant role. It helps us in determining its temperature. It ranges from reddish color to a bluish-white color. A red color star indicates that the star is of low temperature, whereas a bluish-white star indicates that the star is of high temperature.

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What best describes the direction of the electric field on a spherical equipotential surface?

Alla [95]

Answer:

Perpendicular to the surface

Explanation:

- Electric field lines represent the direction of the electric field. The electric field lines also correspond to the direction along which the gradient of the electric potential is maximum.

- Equipotentials are lines or surfaces along which the electric potential is constant: the electric potential does not change moving along an equipotential surface.

Given the two definitions, equipotential lines are always perpendicular to the electric field lines. Therefore, in this problem, the direction of the electric field is perpendicular to the spherical equipotential surface.

4 0

3 years ago

A 5 kg wooden block sitson a flat straight-away12 meters fromthe bottom of an infinitely long ramp, which has an angle of 20 deg

saveliy_v [14]

Answer:

(a) 19.71801m/s Velocity just before going up the ramp.

(b) 74.56338m.

Explanation:

We will solve it in two parts, first we will calculate time that 5kg wooden block would take to just reach ramp and with this time we will calculate final velocity that the wooden block would have in this time.

Second, we will calculate the component of velocity vector along inclined plane and the time that it would take for velocity to be 0 meters/s then with this time we will calculate the distance that inclined plane would travel along inclined plane.

Following formulas will be used.

$x(t) = \frac{1}{2} t^2 = 12m =16.2m/s^2 t^2$

$F =ma$

$V(t) = V_{o} +at$

$x(t) = x_{0} +v_{0}t+\frac{1}{2}a t^2$

(a) Calculating velocity right before going up the ramp.

Wooden block is going on a straightaway and has net for on it.

$F_{n} =F-F_{s} = F-uF_{n} = 100N-0.4*9.8m/s^2*5kg$ = $81N$

and this force produces acceleration of

$a = \frac{F}{m}=\frac{81}{5} =16.2m/s^2 .$

With this acceleration, wooden block would reach at the foot of ramp in.

$x(t) = 12m = 16.2m/s^2*t^2$

$t = 1.217s$

and final velocity will be

$v(t) = v_{0}+at = 0+16.2m/s^2*1.2171s = 19.7180m/s.$

this velocity of wooden box just before going up the ramp.

(b) How far up the ramp will the wooden block go before stopping.

Ramp is at 20° relative to horizontal therefore velocity along the ramp that the wooden block would have will be.

$V= V_{h}cos(20) = 18.5288m/s$

and deceleration along the ramp is

$a = \frac{F_{s} }{m}$

Where $F_{s}$ force of friction along the inclined plane.

$F_s = uF_n = u*m*a$

$a = 9.8m/s^2*cos(20) = 9.2089m/s^2$

is a component of g along normal of the inclined plane.

$F_{s} = 0.25*5kg*9.2089m/s^2$

$= 11.5112N$

$a = \frac{11.5112N}{5kg} = 2.3022m/s^2$

And with this deceleration time needed to get wooded block to stop is.

$v(t) = v_o-at = 18.5288m/s-2.3022m/s^2*t = 0$

$t = \frac{18.5288m/s}{2.3022m/s^2} =8.04813s$

and in that time wooden block would travel

$x(8.04813s) = 18.52881m/s *8.04813s-\frac{1}{} 2.3022m/s^2*(8.0481)^2=74.56338m$

This is how up wooden box will go before coming to stop.

3 0

3 years ago

All of the following are physical properties of hydrogen peroxide except it

tankabanditka [31]

The answer to this question is B, Reacts with sunlight.

The 2 main properties of substances are their physical properties and chemical properties.
Physical properties are some observable/measurable characteristics, such as their color, mass, state, melting point, conductivity etc.

Meanwhile, for chemical properties, they're about how the substance reacts with other substances, such as metals react with acid to form hydrogen. And by the word "react", it means there's no way turn the reaction product back to the original substance without using chemical methods such as heating or electrolysis.

Therefore, all the choices above are physical properties of hydrogen peroxide except for B, as it is the only choice that relates to the substance reacting to another substance.

5 0

3 years ago

A 0.150-kg cart that is attached to an ideal spring with a force constant (spring constant) of 3.58 N/m undergoes simple harmoni

SVETLANKA909090 [29]

Answer:

E = 0.01 J

Explanation:

Given that,

The mass of the cart, m = 0.15 kg

The force constant of the spring, k = 3.58 N/m

The amplitude of the oscillations, A = 7.5 cm = 0.075 m

We need to find the total mechanical energy of the system. It can be given by the formula as follows :

$E=\dfrac{1}{2}kA^2$

Put all the values,

$E=\dfrac{1}{2}\times 3.58\times (0.075)^2\\\\=0.01\ J$

So, the value of total mechanical energy is equal to 0.01 J.

3 0

2 years ago

What magnification is best for the observation of most tissue slides? Explain why this has proved to be true?

Komok [63]

Answer:

The 10X objective is use for the identification of actual size of histology tissues and 4X magnification is best for observation of most tissues slides

Explanation:

4X magnification is best for observation of most tissues slides because it has an objective lens that have lower power and have great high field overview which make it very easier to locate specimens on the slide. It is use to get the overview of histology slides. It is use to showcase more detailed observations about histology.

The 40X objective is use majorly to identify tissue , to observe the finer details and study tissue organization on the histology slide.

7 0

3 years ago