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4 years ago

Why are the arms of spiral galaxies typically blue in color?

Physics

1 answer:

Rus_ich [418]4 years ago

3 0

Answer:

Stars are forming in the spiral arms so there are high mass, hot, blue stars in the arms.

Explanation:

You might be interested in

How much time is needed to produce 900 Joules of work if 120 watts of power is used?

Charra [1.4K]

Answer:

7.5 seconds

Explanation:

because wattsXtime=Joules so 120X__=900. 900 divided by 120= 7.5

6 0

3 years ago

A 1.94-m-diameter lead sphere has a mass of 5681 kg. A dust particle rests on the surface. What is the ratio of the gravitationa

scoundrel [369]

To develop this problem we will apply Newton's laws regarding gravitational forces, both in space and on earth. From finding this relationship, leaving the variable of the dust mass open, we will find the relationship of the forces between the two surfaces. Our values are,

$\text{Diameter of the lead sphere} = D=1.940m$

$\text{Mass of the lead sphere} = m_1 = 5681kg$

$\text{Mass of the dust particle} = m_2$

Distance between the center of lead sphere to dust particle

$r = \frac{D}{2}$

$r = \frac{1.940m}{2}$

$r = 0.97m$

Gravitational force of the sphere on the dust particle:

$F = \frac{Gm_1m_2}{r^2}$

$F = \frac{(6.67*10^{-11}N\cdot m^2/kg^2)(5681kg)(m_2)}{(0.97m)^2}$

$F = (4.027*10^{-7} N/kg)m_2$

Weight of the dust particle

$W = m_2 g$

$W = m_2 (9.8m/s^2)$

Ratio of F and W:

$\frac{F}{W} = \frac{(4.07*10^{-7}N/kg) m_2)}{m_2(9.8m/s^2)}$

$\frac{F}{W} = 4.153*10^{-8}$

Therefore the ratio is $4.153*10^{-8}$

3 0

3 years ago

1. A book resting on a shelf was found

Alex

Answer:

12J

Explanation:

Right before it hits the ground, the initial potential energy and the final kinetic energy will equal each other due to conservation of energy.

3 0

3 years ago

(a) If the coefficient of kinetic friction between tires and dry pavement is 0.80, what is the shortest distance in which you ca

Colt1911 [192]

a) 52.5 m

b) 16.0 m/s

Explanation:

The motion of a car slowed down by friction is a uniformly accelerated motion, so we can use the following suvat equation:

$v^2-u^2=2as$

where

v = 0 is the final velocity (the car comes to a stop)

u = 28.7 m/s is the initial velocity of the car

a is the acceleration

s is the stopping distance

For a car acted upon the force of friction, the acceleration is given by the ratio between the force of friction and the mass of the car, so:

$a=\frac{-\mu mg}{m}=-\mu g$

where:

$\mu=0.80$ is the coefficient of friction

$g=9.8 m/s^2$ is the acceleration due to gravity

Substituting and solving for s, we find:

$s=\frac{v^2-u^2}{-2\mu g}=\frac{0-(28.7)^2}{-2(0.80)(9.8)}=52.5 m$

In this case, the car is moving on a wet road. Therefore, the coefficient of kinetic friction is

$\mu=0.25$

Here we want the stopping distance of the car to remain the same as part a), so

$s=52.5 m$

We can use again the same suvat equation:

$v^2-u^2=2as$

And since the final velocity is zero

u = 0

We can find the initial velocity of the car:

$v=\sqrt{2as}=\sqrt{2\mu gs}=\sqrt{2(0.25)(9.8)(52.5)}=16.0 m/s$

7 0

3 years ago

The mechanical energy of a 2kg body is 35J and its potential energy is 10J calculate speed energy

Anna11 [10]

Answer:

Explanation:

20 multiplied by 2

hope i hv answered ur question

5 0

3 years ago