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3 years ago

PLSSSS HELPPPP PLSSSS 25 POINTS PLS I REALLY NEED THIS AND GET THEM RIGHT SO PLS DONT ANSWER IF U DONT KNOW

Physics

2 answers:

denis23 [38]3 years ago

4 0

Answer:

1- C 2-B 3-B - these are ur best answers

Explanation:

cupoosta [38]3 years ago

3 0

Answer:

1. C(bone structure)

2. B (Common ancestor)

3.D (DNA)

Explanation:

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Place the following list in order of occurrence from oldest to most recent:

Andre45 [30]

Answer:

Explanation:

2.Big bang, 3.contraction of the solar nebula, 5.stellar ignition in our sun, 4.outgassing of earths secondary atmosphere, 1.appearance of the first ocean on earth ,7.evolution of photosynthesis, 6.build- up of oxygen in earths atmosphere.

4 0

2 years ago

How far will a bird have traveled in 13 seconds if it maintains a speed of 31 m/s

BARSIC [14]

Distance = Speed × time

Distance = 31m/s × 13 seconds = 403m

8 0

2 years ago

A 2.3 kg block of copper is heated at atmospheric pressure such that its temperature increases from 6 oC to 90 oC. How much heat

Shtirlitz [24]

Answer:

the heat absorbed by the block of copper is 74368.476J

Explanation:

Hello!

To solve this problem use the first law of thermodynamics that states that the heat applied to a system is the difference between the initial and final energy considering that the mass and the specific heat do not change so we can infer the following equation

Q=mCp(T2-T1)

Where

Q=heat

m=mass=2.3kg

Cp=0.092 kcal/(kg C)=384.93J/kgK

T2=Final temperatura= 90C

T1= initial temperature=6 C

solving

$Q=(2.3kg)(384.93\frac{J}{kgC} )(90C-6C)=74368.476J$

the heat absorbed by the block of copper is 74368.476J

7 0

3 years ago

Would water molecules in Venus’ atmosphere, whose temperature is 740 K, escape into outer space? A water molecule has a mass tha

Akimi4 [234]

Answer:

The water molecule cannot escape, since the average velocity of the water molecules is less than one sixth of the escape velocity of venus.

Explanation:

The average speed of gas molecules is given by:

$v_{rms}=\sqrt{\frac{3RT}{M}}$

R is the gas constant, T is the temperature and M the molar mass of the gas.

We know that a water molecule has a mass that is 18 times that of a hydrogen atom:

$M_H=1.01*10^{-3}\frac{kg}{mol}\\M_{H2O}=18M_H=0.02\frac{kg}{mol}$

So, we have:

$v_{rms}=\sqrt{\frac{3(8.314\frac{J}{mol \cdot K})740K}{0.02\frac{kg}{mol}}}\\v_{rms}=960.65\frac{m}{s}*\frac{1km}{1000m}=0.96\frac{km}{s}$

The water molecule cannot escape, since the average velocity of the water molecules is less than one sixth of the escape velocity of venus:

$10\frac{km}{s}*\frac{1}{6}=1.6\frac{km}{s}\\0.96\frac{km}{s}$

4 0

3 years ago

Select all that apply

borishaifa [10]

a,b,c is your answer light and sound are not considered matter and heat is energy created from matter and electricity is particles moving basically therefore electricity is matter hope this helps

5 0

3 years ago