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2 years ago

A cyclist reaches the top of a hill with

Physics

1 answer:

rjkz [21]2 years ago

5 0

Answer:Based on the excerpt, which best describes Harburg’s view of the Great Depression?

He has no interest in financial success for himself.

He values artistic success over financial success for himself.

He believes most people benefited from losing their financial stability.

He regrets the fact that he gave away his money to benefit his art.

Explanation:

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Problem 1: Spherical mirrorConsider a spherical mirror of radius 2 m, and rays which go parallel to the optic axis. What is thep

SIZIF [17.4K]

Answer:

1) iii i= 1m, 2) iii and iv, 3) i = f₂ (L-f₁) / (L - (f₁ + f₂))

Explanation:

Problem 1

For this problem we use two equations the equations of the focal distance in mirrors

f = r / 2

f = 2/2

f = 1 m

The builder's equation

1 / f = 1 / o + 1 / i

Where f is the focal length, "o and i" are the distance to the object and the image respectively.

For a ray to arrive parallel to the surface it must come from infinity, whereby o = ∞ and 1 / o = 0

1 / f = 0 + 1 / i

i = f

i = 1 m

The image is formed at the focal point

The correct answer is iii

Problem 2

For this problem we have two possibilities the lens is convergent or divergent, in both cases the back face (R₂) must be flat

Case 1 Flat lens - convex (convergent)

R₂ = infinity

R₁ > 0

Cas2 Flat-concave (divergent) lens

R₂ = infinity

R₁ <0

Why the correct answers are iii and iv

Problem 3

For a thick lens the rays parallel to the first surface fall in their focal length (f₁), this is the exit point for the second surface whereby the distance to the object is o = L –f₁, let's apply the constructor equation to this second surface

1 / f₂ = 1 / (L-f₁) + 1 / i

1 / i = 1 / f₂ - 1 / (L-f₁)

1 / i = (L-f₁-f₂) / f₂ (L-f₁)

i = f₂ (L-f₁) / (L - (f₁ + f₂))

This is the image of the rays that enter parallel to the first surface

6 0

3 years ago

un litro de un gas es calentado a presión constante desde 20°C hasta 60°C que volumen final ocupará dicho gas?

WINSTONCH [101]

Answer:

Final volume, V2 = 3 Litres

Explanation:

Given the following data;

Initial volume, V1 = 1 litre

Initial temperature, T1 = 20°C

Final temperature, T2 = 60°C

To find the final volume, we would use Charles' law;

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles is given by;

V1/T1 = V2/T2

Making V2 as the subject formula, we have;

V1T2 = V2T1

V2 = (V1T2)/T1

Substituting into the formula, we have;

V2 = (1 * 60)/20

V2 = 60/20

Final volume, V2 = 3 Litres

4 0

3 years ago

What is the combined resistance for two resistors with resistances of 10 Ohms and 23.7 Ohms if they are connected in series

Agata [3.3K]

Answer: 33.7Ω

Explanation:

Since there are two resistors connected in series, the total resistance (Rtotal) of the circuit is the sum of each resistance.

i.e Rtotal = R1 + R2

R1 = 10Ω

R2 = 23.7Ω

Hence, Rtotal = 10Ω + 23.7Ω

Rtotal = 33.7Ω

Thus, the combined resistance for two resistors is 33.7Ω

3 0

3 years ago

Air enters a turbine operating at steady state at 8 bar, 1600 K and expands to 0.8 bar. The turbine is well insulated, and kinet

kobusy [5.1K]

Answer:

the maximum theoretical work that could be developed by the turbine is 775.140kJ/kg

Explanation:

To solve this problem it is necessary to apply the concepts related to the adiabatic process that relate the temperature and pressure variables

Mathematically this can be determined as

$\frac{T_2}{T_1} = (\frac{P_2}{P_1})^{(\frac{\gamma-1}{\gamma})}$

Where

Temperature at inlet of turbine

Temperature at exit of turbine

Pressure at exit of turbine

The steady flow Energy equation for an open system is given as follows:

$m_i = m_0 = mm(h_i+\frac{V_i^2}{2}+gZ_i)+Q = m(h_0+\frac{V_0^2}{2}+gZ_0)+W$

Where,

m = mass

m(i) = mass at inlet

m(o)= Mass at outlet

h(i)= Enthalpy at inlet

h(o)= Enthalpy at outlet

W = Work done

Q = Heat transferred

v(i) = Velocity at inlet

v(o)= Velocity at outlet

Z(i)= Height at inlet

Z(o)= Height at outlet

For the insulated system with neglecting kinetic and potential energy effects

$h_i = h_0 + WW = h_i -h_0$

Using the relation T-P we can find the final temperature:

$\frac{T_2}{T_1} = (\frac{P_2}{P_1})^{(\frac{\gamma-1}{\gamma})}\\$

$\frac{T_2}{1600K} = (\frac{0.8bar}{8nar})^{(\frac{1.4-1}{1.4})}\\ = 828.716K$

From this point we can find the work done using the value of the specific heat of the air that is 1,005kJ / kgK

$W = h_i -h_0W = C_p (T_1-T_2)W = 1.005(1600 - 828.716)W = 775.140kJ/Kg$

the maximum theoretical work that could be developed by the turbine is 775.140kJ/kg

4 0

3 years ago

Filiberto va a 90m/s en su carri, de repente se distrae por un par de segundos y su velocdad pasa a 40 m/s ¿cual fue su acelerac

svet-max [94.6K]

Answer:

Filiberto experimenta una deceleración de $2\,\frac{m}{s^{2}}$ .

Explanation:

(The problem was written in Spanish. Hence, explanation will be held in Spanish).

Asúmase que Filiberto se distrae por 2 segundos, puesto que un par equivale a dos, y que el vehículo experimenta un aceleración constante. La deceleración experimentada por el vehículo se deriva de la siguiente fórmula:

$a = \frac{v-v_{o}}{\Delta t}$

$a = \frac{40\,\frac{m}{s}-90\,\frac{m}{s} }{2\,s}$

$a = -25\,\frac{m}{s^{2}}$

Filiberto experimenta una deceleración de $2\,\frac{m}{s^{2}}$ .

7 0

3 years ago