All categories

2 years ago

How can one explain the fact that nearly all other galaxies appear to be moving farther away from us?

2 answers:

6 0

<span>How can one explain the fact that nearly all other galaxies appear to be moving farther away from us?

</span>
<span>a) the universe is expanding

</span>

juin [17]2 years ago

4 0

A) the universe is expanding
Every galaxy is moving away from each other - not just us. And the further they are away, the faster they are moving

You might be interested in

Identify one harmful environmental change that occurs when a volcano erupts.

klasskru [66]

Many ecosystems and plants are damaged or destroyed when a volcano erupts.

5 0

3 years ago

The atomic mass of an element is

inessss [21]

Here are the answers to the question. Make sure to give a valid reason, please.

A. the sum of the protons and neutrons in one atom of the element.

B. a ratio based on the mass of a carbon-12 atom.

C. a weighted average of the masses of an element's isotopes.

D. twice the number of protons in one atom of the element.

6 0

3 years ago

a train traveling at 30m/s comes to a complete stop in 20 sec.how far did the train go during the deceleration

elixir [45]

Answer:

600m

Explanation:

v=30m/s

t=20s

s=VT

20×30=600m

3 0

3 years ago

Lena helps a child who is choking on his food. Which reliable method prepared her for helping with this injury?

Ivanshal [37]

knowledge of first aid ... eg St John Ambulance, Red Cross etc. I think that everyone in a school should be taught First Aid.

7 0

2 years ago

Read 2 more answers

If two objects A and B have the same kinetic energy but A has three times the momentum of B, what is the ratio of their inertias

Thepotemich [5.8K]

Answer:

$\frac{inertia_B}{inertia_A}=9$

Explanation:

First of all, let's remind that:

- The kinetic energy of an object is given by $K=\frac{1}{2}mv^2$ , where m is the mass and v is the speed

- The momentum of an object is given by $p=mv$

- The inertia of an object is proportional to its mass, so we can write $I=km$ , where k just indicates a constant of proportionality

In this problem, we have:

- $K_A = K_B$ (the two objects have same kinetic energy)

- $p_A = 3 p_B$ (A has three times the momentum of B)

Re-writing both equation we have:

$\frac{1}{2}m_A v_A^2 = \frac{1}{2}m_B v_B^2\\m_A v_A = 3 m_B v_B$

If we divide first equation by second one we get

$v_A = 3 v_B$

And if we substitute it into the first equation we get

$m_A (3 v_B)^2 = m_B v_B^2\\9 m_A v_B^2 = m_B v_B^2\\m_B = 9 m_A$

So, B has 9 times more mass than A, and so B has 9 times more inertia than A, and their ratio is:

$\frac{I_B}{I_A}=\frac{km_B}{km_A}=\frac{9m_A}{m_A}=9$

7 0

3 years ago