In which direction will the object accelerate?

Which of the following processes are spontaneous? Check all that apply.

-Dominant- [34]

Answer:

(1) A hot drink cooling to room temperature.

(2) The combustion of natural gas.

Explanation:

The spontaneous process is the process in which there is a release of energy and moves towards lower energy and a more thermodynamically stable energy state. All the natural processes are spontaneous.

There are two processes which are spontaneous in the given question are:

(1) A hot drink cooling to room temperature: In this, there is a decrease in energy and also it is a natural process and we know that all the natural processes are spontaneous.

(2) The combustion of natural gas: The fire is an example of an exothermic reaction. The combustion is a combination of a decrease in energy and an increase in entropy. So, this process occurs spontaneously.

5 0

2 years ago

A 40-kg rock is dropped from an elevation of 10 m. What is the velocity of the rock when it is 5-m from the ground?

ivolga24 [154]

Answer:

Explanation:

Given

mass of rock $m=40\ kg$

Elevation of Rock $h=10\ m$

Distance traveled by rock with time

$h=ut+\frac{1}{2}at^2$

where, u=initial velocity

t=time

a=acceleration

here initial velocity is zero

when rock is 5 m from ground then it has traveled a distance of 5 m from top because total height is 10 m

$5=0\times t+\frac{1}{2}(9.8)(t^2)$

$t^2=\frac{10}{9.8}$

$t=1.004\approx 1\ s$

velocity at this time

$v=u+at$

$v=0+9.8\times 1.004$

$v=9.83\ m/s$

6 0

3 years ago

A 3-m-high, 7-m-wide rectangular gate is hinged at the top edge and is restrained by a fixed ridge. Determine the hydrostatic fo

Shalnov [3]

Answer:

The Hydrostatic force is $F = 137.2 kN$

The location of pressure center is $Z = 1.333 \ m$

Explanation:

From the question we are told that

The height of the gate is $h = 3 \ m$

The weight of the gate is $w = 7 \ m$

The height of the water is $h_w = 2 \ m$

The density of water is $\rho_w = 1000 \ kg/m^3$

Note used $h_w$ for height of water and height of gate immersed by water since both have the same value

The area of the gate immersed in water is mathematically represented as

$A = h_w * w$

substituting values

$A = 2* 7$

$A = 14 \ m^2$

The hydrostatic force is mathematically represented as

$F = \rho_w * g * h_f * A$

Where

$h_f =h- h_w$

$h_f =3 -2$

$h_f = 1\ m$

So

$F = 1000 * 9.8 * 1 * 14$

$F = 137.2 kN$

The center of pressure is mathematically represented as

$Z = h_f + \frac{I_g}{h_f * A}$

Where $I_g$ is the moment of inertia of the gate which mathematically represented as

$I_g = \frac{w * h_w^2}{12}$

The $h_w$ is the height of gate immersed in water

$I_g = \frac{7 * 2^2 }{12}$

$I_g = 4.667\ kg m^2$

Thus

$Z = 1 + \frac{4.66}{1 * 14}$

$Z = 1.333 \ m$

3 0

2 years ago

What do ocean waves and sound waves have in common?

Anettt [7]

Since they are both examples of moving waves, they both transmit energy.

7 0

3 years ago

Read 2 more answers

Calculate the de broglie wavelength (in picometers) of a hydrogen atom traveling at 440 m/s.

Aleonysh [2.5K]

De broglie wavelength, $\lambda = \frac{h}{mv}$ , where h is the Planck's constant, m is the mass and v is the velocity.

$h = 6.63*10^{-34}$

Mass of hydrogen atom, $m = 1.67*10^{-27}kg$

v = 440 m/s

Substituting

Wavelength $\lambda = \frac{h}{mv} = \frac{6.63*10^{-34}}{1.67*10^{-27}*440} = 0.902 *10^{-9}m = 902 *10^{-12}m$

$1 pm = 10^{-12}m\\ \\ So , \lambda =902 pm$

So the de broglie wavelength (in picometers) of a hydrogen atom traveling at 440 m/s is 902 pm

7 0

2 years ago