(No files or links) Which of the following is a defining property of gases?

How long ago did homo sapiens first appeared in the fossil record? Identify the era in which this occurred.

AVprozaik [17]

First discovery - Herto, Ethopia. 160,000 years ago - 40,000 years earlier than the previous oldest remains homo sapiens.

3 0

3 years ago

Read 2 more answers

Problem 1. Cylinders and a pendulum A uniform solid cylinder of radius r and mass m can roll inside a hollow cylinder of radius

Nataliya [291]

Answer:

The two answers are in the explanation

Explanation:

Please find the attached files for the solution

7 0

4 years ago

Suppose the voltage source for a series RL-circuit were given as V0sin(ωt) instead of V0cos(ωt). Write an expression for the cur

Gala2k [10]

Answer:

Explanation:

This is an RL circuit, therefore:

Impedance; z = $\mathbf{\sqrt{R^2+L^2}}$

$\mathbf{z = \sqrt{R^2+(Lw)^2}}$

Current amplitude

$\mathbf{I_o = \dfrac{V_o}{z}} \\ \\ \mathbf{I_o = \dfrac{V_o}{\sqrt{R^2+L^2\omega ^2}}}$

a)

Given that:

$V_o = 1.9 \ V \\ \\ \omega= 51 \ rad/s\\\\ R = 21 \Omega \\ \\ L = 0.52 H$

∴

$I_o= \dfrac{1.9}{\sqrt{21^2+(0.52\times 51)^2}}$

$\mathbf{I_o= 0.0562} \\ \\ \mathbf{I_o = 56.2 \ mA}$

b)

Phase constant :

$tan \ \phi = \dfrac{L \omega}{R } \\ \\ tan \ \phi = \dfrac{0.52 \times 51}{21} \\ \\ tan \phi = 1.263$

$\text{Phase constant : }\phi = tan^{-1} (1.263) \\ \\ \phi = 51.6^0\\ \\\text{To radians} \phi = 51.6 \times \dfrac{\pi}{180} \\ \\ \phi = 0.287 \pi \\ \\ \mathbf{\phi = 0.9 \ rad}$

3 0

3 years ago

Please help me with homework

Stells [14]

<h3><u>Answer;</u></h3>

= 64 N/m

<h3><u>Explanation</u>;</h3>

According to Hooke's Law for a helical spring or an elastic material, extensional force is directly proportional to the distance the material has extended.

F = ke; where F is the extension force, k is the spring constant, and e is the distance extended.

Thus;

k = F/e

= 44N/0.69 m

= 63.768 N/m

<u>= 64 N/m</u>

8 0

3 years ago

A merry-go-round is rotating at an angular speed of 0.2 radians/s. Its motor falls off and it rotates freely. A technician jumps

I am Lyosha [343]

Answer:

I₁ =1250 kg.m²

Explanation:

Given that

Angular speed of Merry ,ω₁= 0.2 rad/s

Angular speed of technician ,ω₂= 0.04 rad/s

Moment of the inertia of the technician ,I₂= 5000 kg.m²

Lets assume that

Moment of the inertia of merry with respected to the ground=I₁

There is no any external torque ,that is why angular momentum of the system will be conserve.

Now by conserving angular momentum

I₁ ω₁=(I₁+I₂)ω₂

I₁ x 0.2 = (I₁ +5000 ) x 0.04

I₁ (0.2-0.04) = 5000 x 0.04

$I_1=\dfrac{5000\times 0.04}{0.2-0.04}$

I₁ =1250 kg.m²

5 0

3 years ago