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3 years ago

Explain why astronomers have deduced that galaxies contain a large quantity of dark matter

1 answer:

3 0

Dark matter is studied by astronomers by observing the effect it has on visible objects. This is because dark matter itself is not detectable. Astronomers think that some galaxies might have a lot of dark matter because of the unexplainable motion of stars in these galaxies.

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Need help, marking brainliest:)

katrin2010 [14]

Answer:

Always

Explanation:

Unbalanced forces means an acceleration, meaning a change in speed!

5 0

3 years ago

An elevator lifts a total mass of 1800 kg, a distance of 60 m in 60 s. How much power does the elevator generate?

emmainna [20.7K]

Answer:

17640

Explanation:

Power = workdone/time

Power = (force x displacement)/time

Power = (mg x 60)/60

Power = (1800 x 9.8 x 60)/60

=> power = 17640 watt

3 0

3 years ago

Donovan claims that the immune system works with other body systems. Is he correct? Explain.

djverab [1.8K]

Yes it does work with the other body system

8 0

3 years ago

Read 2 more answers

Driving on asphalt roads entails very little rolling resistance, so most of the energy of the engine goes to overcoming air resi

trapecia [35]

Answer:

a) $F_p=882N$

b) $P=4410W$

c) $V_p'=24135$ , $n=15.2\%$

Explanation:

From the question we are told that:

Mass $M=1500kg$

Velocity $v=4.9m/s$

Coefficient of Rolling Friction $\mu=0.06$

Generally the equation for The Propulsion Force is mathematically given by

$F_p=\mu*mg$

$F_p=0.06*1500*9.81$

$F_p=882N$

Therefore Power Required at

$V_p=5.0m/s$

$P=F_p*V_p$

$P=882*5$

$P=4410W$

$V_p' =15mpg$

$V_p'=15*\frac{1609}$

$V_p'=24135$

Generally the equation for Work-done is mathematically given by

$W=F_p*V_p'$

$W=882*15*1609$

$W=2.13*10^7$

Therefore

Efficiency

$n=\frac{W}{E}*100\%$

Since

Energy in one gallon of gas is

$E=1.4*10^8J$

Therefore

$n=\frac{2.1*10^7}{1.4*10^8}*100\%$

$n=15.2\%$

7 0

3 years ago

An object is thrown straight up with an initial velocity of 3 m/s. what is its acceleration at its maximum height?

Mama L [17]

At it's maximum height the acceleration is still 9.8m/s. On the earths surface, all objects are constantly under acceleration due to gravity. It is perculiar, but true. Under acceleration, only the velocity changes (as a general rule).

6 0

3 years ago