Which of the following is necessary for the greenhouse effect?

Simora [160]

I only know what number 1. is and its Mechanical Energy.

8 0

3 years ago

Some element can be either solid or liquid. At the melting point, the liquid has 8 × 10-22 J more enthalpy per atom than the sol

OlgaM077 [116]

Answer:

481.76 J/mol

133.33 K

Explanation:

$N_A$ = Avogadro's number = $6.022\times 10^{23}$

Change in enthalpy is given by

$\Delta H=8\times 10^{-22}\times 6.022\times 10^{23}\\\Rightarrow \Delta H=481.76\ J/mol$

Entropy is given by

$\Delta S=6\times 10^{-24}\times 6.022\times 10^{23}\\\Rightarrow \Delta S=3.6132\ J/mol K$

Latent heat of fusion is given by

$L_f=\Delta H\\\Rightarrow L_f=481.76\ J/mol$

The latent heat of fusion is 481.76 J/mol

Melting point is given by

$T_m=\dfrac{L_f}{\Delta S}\\\Rightarrow T_m=\dfrac{8\times 10^{-22}\times 6.022\times 10^{23}}{6\times 10^{-24}\times 6.022\times 10^{23}}\\\Rightarrow T_f=133.33\ K$

Melting occurs at 133.33 K

3 0

3 years ago

What would be the speed of an object just before hitting the ground if dropped 100 meters?

PolarNik [594]

<u>We are given:</u>

the initial height of the object (h) = 100 m

initial velocity (u) = 0 m/s

we will let the value of g = 10 m/s/s

<u>Speed of the object just before hitting the ground:</u>

From the third equation of motion:

v² - u² = 2ah (where v is the final velocity)

replacing the variables, we get:

v² - (0)² = 2(10)(100)

v² = 2000

v = 10√20 = 44.7 m/s

Therefore, the speed of the object just before hitting the ground is 44.7 m/s

8 0

4 years ago

Quddus and Saadman start running together from the same point. Quddus runs at constant velocity 0.5ms−1. Saadman’s initial veloc

svp [43]

Answer:

the answer is C.

Explanation:

8 0

2 years ago

A ball is whirled on the end of a string in a horizontal circle of radius R at const v. By which one of the following means can

denpristay [2]

Answer:

D

Explanation:

Centripetal acceleration is the square of velocity divided by radius:

a = v² / r

Velocity is equal to angular velocity times radius, so this can also be written as:

a = ω² r

And angular velocity is 2π divided by the period, so:

a = (2π / T)² r

We can use these two equations to determine which scenario results in double the centripetal acceleration.

A) Keep the radius fixed and increase the period by a factor of two.

(2π / 2T)² r

1/4 (2π / T)² r

1/4 a

B) Keep the radius fixed and decrease the period by a factor of two.

(2π / ½T)² r

4 (2π / T)² r

4a

C) Keep the speed fixed and increase the radius by a factor of two.

v² / 2r

1/2 a

D) Keep the speed fixed and decrease the radius by a factor of two.

v² / ½r

2a

Only D doubles the centripetal acceleration.

8 0

3 years ago