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Setler79 [48]
3 years ago
7

Imagine you leave the dock on a fishing boat that travels east for 30 kilometers when the captain realizes he left the fishing r

ods on the dock. It takes him 40 minutes to travel out against the current but only 20 minutes to return to the dock.
Physics
1 answer:
telo118 [61]3 years ago
3 0

Answer:

Average speed is 60 km/hr whereas average velocity is 0 km/ hr.

Explanation:

The average speed of the boat is 60 km/ hr while on the other hand, the average velocity of the boat is 0 km/ hr because average speed is the total distance covered by the boat in total time and average velocity is the displacement covered by the boat in total time. The total distance covered by the boat is 60 km and the total time is 60 minutes which is equals to one hour so the answer is 60 km/hr whereas the displacement is the shortest distance between initial and final position which is 0 in this case so 0 divided by 60 minutes or one hour is also 0.

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An electron and a proton each have a thermal kinetic energy of 3kBT/2. Calculate the de Broglie wavelength of each particle at a
IgorLugansk [536]

Answer:

The de Broglie wavelength of electron βe = 2.443422 × 10⁻⁹ m

The de Broglie wavelength of proton βp = 5.70 × 10⁻¹¹ m

Explanation:

Thermal kinetic energy of electron or proton = KE

∴ KE = 3kbT/2

given that; kb = 1.38 x 10⁻²³ J/K , T = 1950 K

so we substitute

KE = ( 3 × 1.38 x 10⁻²³ × 1950 ) / 2

kE = 4.0365 × 10⁻²⁰ (  is the kinetic energy for both electron and proton at temperature T )

Now we know that

mass of electron M'e = 9.109 ×  10⁻³¹

mass of proton M'p = 1.6726 ×  10⁻²⁷

We also know that

KE = p₂ / 2m

from the equation, p = √ (2mKE)

{ p is momentum, m is mass }

de Broglie wavelength = β

so β = h / p = h / √ (2mKE)

h = Planck's constant = 6.626 ×  10⁻³⁴

∴ βe =  h / √ (2m'e × KE)

βe = 6.626 ×  10⁻³⁴ / √ (2 × 9.109 ×  10⁻³¹ × 4.0365 × 10⁻²⁰ )

βe = 6.626 ×  10⁻³⁴ / √  7.3536957 × 10⁻⁵⁰

βe = 6.626 × 10⁻³⁴  / 2.71176984642871 × 10⁻²⁵

βe = 2.443422 × 10⁻⁹ m

βp =  h / √ (2m'p ×KE)

βp = 6.626 ×  10⁻³⁴ / √ (2 × 1.6726 ×  10⁻²⁷ × 4.0365 × 10⁻²⁰ )

βp = 6.626 ×  10⁻³⁴ / √ 1.35028998 × 10⁻⁴⁶

βp =  6.626 ×  10⁻³⁴ / 1.16201978468527 ×  10⁻²³

βp = 5.702140 × 10⁻¹¹ m

3 0
3 years ago
Two electrons exert a force of repulsion of 1.2 N on each other. How far apart are they? The elementary charge is 1.602 × 10−19
aleksandr82 [10.1K]

Answer:

The answer to your question is distance between these electrons

                                                   = 1.386 x 10⁻¹⁴ m

Explanation:

Data

Force = F = 1.2 N

distance = d = ?

charge = q₁ = q₂ = 1.602 x 10⁻¹⁹ C

K = 8.987 x 10⁹ Nm²/C²

Formula

-To solve this problem use the Coulomb's equation

  F = kq₁q₂ / r²

-Solve for r²

  r² = kq₁q₂ / F

-Substitution

  r² = (8.987 x 10⁹)(1.602 x 10⁻¹⁹)(1.602 x 10⁻¹⁹) / 1.2

- Simplification

  r² = 2.306 x 10⁻²⁸ / 1.2

  r² = 1.922 x 10⁻²⁸

-Result

  r = 1.386 x 10⁻¹⁴ m

7 0
4 years ago
An engine is designed to obtain energy from the temperature gradient of the ocean. What is the thermodynamic efficiency of such
rewona [7]

Answer:

0.035 (3.5 %)

Explanation:

The thermodynamic efficiency is given by:

\eta = 1 - \frac{T_C}{T_H}

where

T_C is the cold temperature

T_H is the hot temperature

In this problem we have

T_C = 5 ^{\circ}C+ 273 = 278 KT_H = 15^{\circ}C+273 = 288 K

So the efficiency is

\eta = 1 - \frac{278 K}{288 K}=0.035

6 0
3 years ago
1. Calcular la masa de mercurio que pasó de 30 °C hasta 120 °C y absorbió 4400 cal. Calor específico del
timofeeve [1]

Answer:

Masa, m = 0.088 kg

Explanation:

Given the following data;

Temperatura inicial = 30°C

Temperatura final = 120°C

Capacidad calorífica específica = 138J/kg.K

Calor absorbido, Q = 4400 cal.

Para encontrar la masa;

La capacidad calorífica viene dada por la fórmula;

Q = mct

Dónde;

Q representa la capacidad calorífica o la cantidad de calor.

m representa la masa de un objeto.

c representa la capacidad calorífica específica del agua.

dt representa el cambio de temperatura.

dt = T2 - T1

dt = 120 - 30

dt = 90°C to kelvin = 273 + 90 = 363K

Sustituyendo en la fórmula, tenemos;

4400 = m*138*363

4400 = 50094m

m = \frac {4400}{50094}

Masa, m = 0.088 kg

7 0
3 years ago
How much heat is needed to raise the temperature of 7g of Water by 20° C
beks73 [17]

the answer to your question is 10.5 kJ

6 0
3 years ago
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