In most cases, what happens to a liquid when it cools?

Pls help‼️Help me with these questions! :/

TiliK225 [7]

Answer:

No number answer; don't want to pull out a calculator lol

Explanation:

Capacitors are added in parallel; opposite of resistors.

So for 9, add 10 and 2.5 then do ((1/12.5)+(1/.3))^-1.

For 10, add 0.75 and 15 first, then the rest is the same idea as 9.

4 0

3 years ago

What are the SI units of thermal conductivity?

kotykmax [81]

Answer:

The SI unit of thermal conductivity is watts per meter-kelvin (W/(m⋅K)).

Explanation:

hope this will help u

7 0

3 years ago

A.complete the following sentences with your own result or condition

ludmilkaskok [199]

1. If I hadn't bought that car yesterday.

2. I would have never bought the tickets for today..

3. She wouldn't have gotten suspended.

4. We could've worked on our project.

5. but I was in the shower.

6 0

3 years ago

I need answers and solvings to these questions

den301095 [7]

1) The period of a simple pendulum depends on B) III. only (the length of the pendulum)

2) The angular acceleration is C) $15.7 rad/s^2$

3) The frequency of the oscillation is C) 1.6 Hz

4) The period of vibration is B) 0.6 s

5) The diameter of the nozzle is A) 5.0 mm

6) The force that must be applied is B) 266.7 N

Explanation:

1)

The period of a simple pendulum is given by

$T=2\pi \sqrt{\frac{L}{g}}$

where

T is the period

L is the length of the pendulum

g is the acceleration of gravity

From the equation, we see that the period of the pendulum depends only on its length and on the acceleration of gravity, while there is no dependence on the mass of the pendulum or on the amplitude of oscillation. Therefore, the correct option is

B) III. only (the length of the pendulum)

2)

The angular acceleration of the rotating disc is given by the equation

$\alpha = \frac{\omega_f - \omega_i}{t}$

where

$\omega_f$ is the final angular velocity

$\omega_i$ is the initial angular velocity

t is the time elapsed

For the compact disc in this problem we have:

$\omega_i = 0$ (since it starts from rest)

$\omega_f = 300 rpm \cdot \frac{2\pi rad/rev}{60 s/min}=31.4 rad/s$ is the final angular velocity

t = 2 s

Substituting, we find

$\alpha = \frac{31.4-0}{2}=15.7 rad/s^2$

3)

For a simple harmonic oscillator, the acceleration and the displacement of the system are related by the equation

$a=-\omega^2 x$

where

a is the acceleration

x is the displacement

$\omega$ is the angular frequency of the system

For the oscillator in this problem, we have the following relationship

$a=-100 x$

which implies that

$\omega^2 = 100$

And so

$\omega = \sqrt{100}=10 rad/s$

Also, the angular frequency is related to the frequency $f$ by

$f=\frac{\omega}{2\pi}$

Therefore, the frequency of this simple harmonic oscillator is

$f=\frac{10}{2\pi}=1.6 Hz$

4)

When the mass is hanging on the sping, the weight of the mass is equal to the restoring force on the spring, so we can write

$mg=kx$

where

m is the mass

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

k is the spring constant

x = 8.0 cm = 0.08 m is the stretching of the spring

We can re-arrange the equation as

$\frac{k}{m}=\frac{g}{x}=\frac{9.8}{0.08}=122.5$

The angular frequency of the spring is given by

$\omega=\sqrt{\frac{k}{m}}=\sqrt{122.5}=11.1 Hz$

And therefore, its period is

$T=\frac{2\pi}{\omega}=\frac{2\pi}{11.1}=0.6 s$

5)

According to the equation of continuity, the volume flow rate must remain constant, so we can write

$A_1 v_1 = A_2 v_2$

where

$A_1 = \pi r_1^2$ is the cross-sectional area of the hose, with $r_1 = 5 mm$ being the radius of the hose

$v_1 = 4 m/s$ is the speed of the petrol in the hose

$A_2 = \pi r_2^2$ is the cross-sectional area of the nozzle, with $r_2$ being the radius of the nozzle

$v_2 = 16 m/s$ is the speed in the nozzle

Solving for $r_2$ , we find the radius of the nozzle:

$\pi r_1^2 v_1 = \pi r_2^2 v_2\\r_2 = r_1 \sqrt{\frac{v_1}{v_2}}=(5)\sqrt{\frac{4}{16}}=2.5 mm$

So, the diameter of the nozzle will be

$d_2 = 2r_2 = 2(2.5)=5.0 mm$

6)

According to the Pascal principle, the pressure on the two pistons is the same, so we can write

$\frac{F_1}{A_1}=\frac{F_2}{A_2}$

where

$F_1$ is the force that must be applied to the small piston

$A_1 = \pi r_1^2$ is the area of the first piston, with $r_1= 2 cm$ being its radius

$F_2 = mg = (1500 kg)(9.8 m/s^2)=14700 N$ is the force applied on the bigger piston (the weight of the car)

$A_2 = \pi r_2^2$ is the area of the bigger piston, with $r_2= 15 cm$ being its radius

Solving for $F_1$ , we find

$F_1 = \frac{F_2A_1}{A_2}=\frac{F_2 \pi r_1^2}{\pi r_2^2}=\frac{(14700)(2)^2}{(15)^2}=261 N$

So, the closest answer is B) 266.7 N.

Learn more about pressure:

brainly.com/question/4868239

brainly.com/question/2438000

#LearnwithBrainly

5 0

3 years ago

1. Indica cuáles son los reactivos y productos de la reacción química representada por la ecuación siguiente, y señala en que es

bearhunter [10]

Answer:

Los reactivos, con su correspondiente estado de agregación, son:

Mg: estado sólido
HCl: estado acuoso

Los productos, con su correspondiente estado de agregación, son:

MgCl₂: estado acuoso
H₂: estado gaseoso

Explanation:

Una reacción química es un proceso por el cual una o más sustancias se transforman en otra u otras sustancias con propiedades diferentes. En otras palabras, las reacciones químicas son procesos en los que los átomos rompen sus enlaces químicos y forman otros nuevos, cambiando la naturaleza de las sustancias que intervienen.

En una ecuación química se representan dos términos. En el primero, el de la derecha, se escriben los reactivos, expresados mediante sus fórmulas químicas correspondientes y separados por un signo más. Por otro lado, el término de la izquierda, en el que aparecen los productos, también representados por sus formulas químicas correspondientes y con signos más entre ellos. Entre ambos términos suele ponerse una flecha que indica que se ha producido la reacción química correspondiente.

Las sustancias que hay antes de producirse el cambio y que desaparecen se llaman reactivos. Las sustancias que hay después de producirse el cambio y que aparecen o se generan se llaman productos.

El estado de agregación en una reacción química se indica poniendo detrás del nombre o la fórmula de la sustancia y entre paréntesis la notación siguiente:

Sustancias sólidas (s)
Sustancias líquidas (l)
Sustancias gaseosas (g)
Sustancias disueltas en agua (aq)

En este caso tienes la reacción química:

Mg (s) + 2 HCl (aq) -> MgCl₂ (aq) + H₂ (g)

Entonces, en este caso los reactivos, con su correspondiente estado de agregación, son:

Mg: estado sólido
HCl: estado acuoso

Por otro lado, los productos, con su correspondiente estado de agregación, son:

MgCl₂: estado acuoso
H₂: estado gaseoso

6 0

3 years ago