All categories

2 years ago

Which term best describes how the solar system formed?.

Physics

1 answer:

FinnZ [79.3K]2 years ago

4 0

Answer:

Approximately 4.6 billion years ago, the solar system was a cloud of dust and gas known as a solar nebula.

Explanation:

You might be interested in

Glass has a hardness that is in the middle of the hardness scale. What is the hardness of Glass?

sweet [91]

Answer: 5.5

Explanation:

Let's start by explaining that hardness is a property that materials have related to the opposition or resistance they offer to alterations such as penetration, abrasion, scratching, cutting, and permanent deformations, among others.

In this context, several hardness scales have been developed to catalog the materials (specifically minerals), being the Mohs scale the best known. This scale, proposed by the German geologist Friedrich Mohs in 1825, consists of a ratio of ten minerals numbered in increasing order by hardness, from least to greatest.

This is how the scale starts at 1 with the talc (considered the softest material) and ends at 10 with the diamond as the hardest.

Now, if we are told that the glass is in the middle of the hardness scale that goes from 1 to 10, logically its value will be 5 (volcanic glass). However, according to the scale, the glass is at 5.5.

8 0

3 years ago

Read 2 more answers

A red blood cell is 7 x 10-6 m in size. This means it is 7 __________ in size. What unit completes the sentence?

aalyn [17]

If a red blood cell is 7 x $10^-^6$ m in size, it means that such a cell is 7 microns or micrometer in size. The unit that completes the sentence will, thus, be microns or micrometer.

According to international system of measurement:

$10^{-1}$ m = decimeter

$10^{-2}$ m = centimeter

$10^{-3}$ m = millimeter
$10^{-6}$ m = micrometer or micron
$10^{-9}$ m = nanometer

Thus, a measurement of 7 x $10^-^6$ m is the same is 7 micons or 7 micrometer.

More on metric conversion can be found here: brainly.com/question/17767575

5 0

2 years ago

PLEASE HELPPPPPPPP<br> What is the average velocity of a train that goes 86 km in 1.3 hours?

olga_2 [115]

The answer is:

V = d/t d = 86 km t = 1.3 hrs

V = 86 km/ 1.3 hrs

V = 66.15 km/ hrs

I hope this helps!!

5 0

2 years ago

Block B is attached to a massless string of length L = 1 m and is free to rotate as a pendulum. The speed of block A after the c

Amanda [17]

Complete Question

The diagram for this question is shown on the first uploaded image

Answer:

The minimum velocity of A is $v_A= 4m/s$

Explanation:

From the question we are told that

The length of the string is $L = 1m$

The initial speed of block A is $u_A$

The final speed of block A is $v_A = \frac{1}{2}u_A$

The initial speed of block B is $u_B = 0$

The mass of block A is $m_A = 7kg$ gh

The mass of block B is $m_B = 2 kg$

According to the principle of conservation of momentum

$m_A u_A + m_B u_B = m_Bv_B + m_A \frac{u_A}{2}$

Since block B at initial is at rest

$m_A u_A = m_Bv_B + m_A \frac{u_A}{2}$

$m_A u_A - m_A \frac{u_A}{2} = m_Bv_B$

$m_A \frac{u_A}{2} = m_Bv_B$

making $v_B$ the subject of the formula

$v_B =m_A \frac{u_A}{2 m_B}$

Substituting values

$v_B =\frac{7 u_A}{4}$

This $v__B$ is the velocity at bottom of the vertical circle just at the collision with mass A

Assuming that block B is swing through the vertical circle(shown on the second uploaded image ) with an angular velocity of $v__B'$ at the top of the vertical circle

The angular centripetal acceleration would be mathematically represented

$a= \frac{v^2_{B}'}{L}$

Note that this acceleration would be toward the center of the circle

Now the forces acting at the top of the circle can be represented mathematically as

$T + mg = m \frac{v^2_{B}'}{L}$

Where T is the tension on the string

According to the law of energy conservation

The energy at bottom of the vertical circle = The energy at the top of

the vertical circle

This can be mathematically represented as

$\frac{1}{2} m(v_B)^2 = \frac{1}{2} mv^2_B' + mg 2L$

From above

$(T + mg) L = m v^2_{B}'$

Substitute this into above equation

$\frac{1}{2} m(\frac{7 v_A}{4} )^2 = \frac{1}{2} (T + mg) L + mg 2L$

$\frac{49 mv_A^2}{16} = \frac{1}{2} (T + mg) L + mg 2L$

$\frac{49 mv_A^2}{16} = T + 5mgL$

The value of velocity of block A needed to cause B be to swing through a complete vertical circle is would be minimum when tension on the string due to the weight of B is zero

This is mathematically represented as

$\frac{49 mv_A^2}{16} = 5mgL$