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2 years ago

What cause the death of stars？

Physics

2 answers:

Alex Ar [27]2 years ago

7 0

Answer:

. When the core runs out of hydrogen fuel, it will contract under the weight of gravity.

Explanation:

fenix001 [56]2 years ago

6 0

Most stars take millions of years to die. When a star like the Sun has burned all of its hydrogen fuel, it expands to become a red giant then when it fully runs out it then dies

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1. You place an object 63 cm in front of a converging lens, with a 40 cm focal length.

NikAS [45]

Answer:

109.6 cm , - 1.74 , real

1.5

Explanation:

d₀ = object distance = 63 cm

f = focal length of the lens = 40 cm

d = image distance = ?

using the lens equation

$\frac{1}{f} = \frac{1}{d_{o}} + \frac{1}{d}$

$\frac{1}{40} = \frac{1}{63} + \frac{1}{d}$

d = 109.6 cm

magnification is given as

$m = \frac{-d}{d_{o}}$

$m = \frac{-109.6}{63}$

m = - 1.74

The image is real

d₀ = object distance = a

d = image distance = - (a + 5)

f = focal length of lens = 30 cm

using the lens equation

$\frac{1}{f} = \frac{1}{d_{o}} + \frac{1}{d}$

$\frac{1}{30} = \frac{1}{a} + \frac{1}{- (a + 5)}$

a = 10

magnification is given as

$m = \frac{-d}{d_{o}}$

$m = \frac{- (- (a +5))}{a}$

$m = \frac{(5 + 10)}{10}$

m = 1.5

6 0

2 years ago

If you cannot get a chair to move across the floor, it is because ___ friction opposes your push.

denis-greek [22]

If you cannot get a chair to move across the floor, it is because static friction opposes your push. When you say static or kinetic friction the two object that facing each other are opposing each other. That's why you're having a hard time pushing the chair.

7 0

3 years ago

A typical running track is an oval with 74-mm-diameter half circles at each end. A runner going once around the track covers a d

lisabon 2012 [21]

The centripetal acceleration a is 4.32 $\times$ 10^-4 m/s^2.

<u>Explanation:</u>

The speed is constant and computing the speed from the distance and time for one full lap.

Given, distance = 400 mm = 0.4 m, Time = 100 s.

Computing the v = 0.4 m / 100 s

v = 4 $\times$ 10^-3 m/s.

radius of the circular end r = 37 mm = 0.037 m.

centripetal acceleration a = v^2 / r

= (4 $\times$ 10^-3)^2 / 0.037

a = 4.32 $\times$ 10^-4 m/s^2.

6 0

2 years ago

Two charges, each q, are separated by a distance r, and exert mutual attractive forces of F on each other. If both charges becom

jeka57 [31]

Answer:

F = ⅔ F₀

Explanation:

For this exercise we use Coulomb's law

F = k q₁q₂ / r²

let's use the subscript "o" for the initial conditions

F₀ = k q² / r²

now the charge changes q₁ = q₂ = 2q and the new distance is r = 3 r

we substitute

F = k 4q² / 9 r²

F = k q² r² 4/9

F = ⅔ F₀

3 0

3 years ago

Consider a household that uses 14,000 kWh of electricity and 900 gal of fuel oil, per year, during a heating season. The average

ryzh [129]

Answer:

9517.2 lbm

Explanation:

Electricity consumption = 14000 kWh/year

Fuel consumption = 900 gal/year

Amount of CO₂ produced per gallon = 26.4 lbm/gal

Amount of CO₂ produced per kWh = 1.54 lbm/kWh

Amount of CO₂ produced in one year

$14000\times 1.54+900\times 26.4=45320\ lbm$

Reduction would be

$0.21\times 45320=9517.2\ lbm$

The reduction in the amount of CO₂ produced is 9517.2 lbm

7 0

3 years ago

What cause the death of stars？​

What cause the death of stars？