By pushing backwards a roller skater moves forward. This is an example of Newton's

It has been suggested that the surface melting of ice plays a role in enabling speed skaters to achieve peak performance. Carry

vesna_86 [32]

Explanation:

Relation between pressure, latent heat of fusion, and change in volume is as follows.

$\frac{dP}{dT} = \frac{L}{T \times \Delta V}$

Also, $\frac{L}{T} = \Delta S^{fusion}_{m}$

where, $\Delta V^{fusion}_{m}$ is the difference in specific volumes.

Hence, $\frac{dP}{dT} = \frac{\Delta S^{fusion}_{m}}{\Delta V^{fusion}_{m}}$

As, $\Delta S^{fusion}_{m} = \frac{L}{T} = \frac{6010}{273.15}$ = 22.0 J/mol K

And, $\Delta V^{fusion}_{m} = \frac{M}{d_{H_{2}O}} - \frac{M}{d_{ice}}$ ...... (1)

where, $d_{H_{2}O}$ = density of water

$d_{ice}$ = density of ice

M = molar mass of water = $18.02 \times 10^{-3} kg$

Therefore, using formula in equation (1) we will calculate the volume of fusion as follows.

$\Delta V^{fusion}_{m} = \frac{M}{d_{H_{2}O}} - \frac{M}{d_{ice}}$

= $\frac{18.02 \times 10^{-3}}{997} - \frac{18.02 \times 10^{-3}}{920}$

= $-1.51 \times 10^{-6}$

Therefore, calculate the required pressure as follows.

$\frac{dP}{dT} = \frac{22}{-1.51 \times 10^{-6}}$

= $1.45 \times 10^{7} Pa/K$

or, = 145 bar/K

Hence, for change of 1 degree pressure the decrease is 145 bar and for 4.7 degree change dP = $145 \times 4.7 bar$

= 681.5 bar

Thus, we can conclude that pressure should be increased by 681.5 bar to cause 4.7 degree change in melting point.

5 0

2 years ago

the frequency of a given region of the electromagnetic spectrum is more than 3 x 10^19HZ. note that the speed of light is 2.998

Cerrena [4.2K]

<span>To solve this problem, You need to look up a picture/diagram of the electromagnetic spectrum. This will have the wave regions listed as well</span> as frequencies and wavelength.
Wavelength is distance/length of one wave, which can be calculated using frequency (hz = s^-1) and the speed of light.
2.998 x 10^8 m/s ÷ 3 x 10^19 s^-1 = 9.99 x 10^-12 m

The Frequency given falls in between X-rays and Gamma rays. The wavelength however; is in the Gama ray region.

5 0

2 years ago

Read 2 more answers

Why don't noble gases bond?

Luba_88 [7]

<span>Their outer shells are filled So much that they don't need to bond or react with any other atoms.</span>

7 0

3 years ago

A bike rider approaches a hill with a speed of 8.5 m/s. The total mass of the bike and the rider is 85 kg. Find the kinetic ener

krek1111 [17]

KE=3070.625 J

Height = 3.686 m

<h3>Further explanation</h3>

mass of bike+rider=85 kg

velocity = 8.5 m/s

$\tt KE=\dfrac{1}{2}mv^2\\\\KE=\dfrac{1}{2}\times 85\times 8.5^2\\\\KE=3070.625~J$

Conservation of energy :

(KE+PE)₁ (downhill) = (KE+PE)₂ (up the hill)

PE₁=0⇒h=0

KE₂=0⇒v=0(stop), so equation becomes :

KE₁=PE₂

$\tt KE_1=3070.625\\\\KE_1=mgh_2\\\\3070.625=85\times 9.8\times h\Rightarrow h=3.686~m$

5 0

3 years ago

What happens to the pressure of a gas inside a rigid container if the temperature of a gas decreases?

NikAS [45]

Answer:

If the temperature of gas is decreased the pressure will also goes to decrease.

Explanation:

The pressure and temperature have direct relation. If the temperature of gas will increase the pressure of gas will also goes to increase.

According to the Gay-Lussas's Law,

The pressure of given amount of gas is directly proportional to the absolute temperature when volume is kept constant.

Mathematical relationship:

P ∝ T

P = kT

P/T = k

and

P₁/T₁ = P₂/T₂

5 0

3 years ago