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2 years ago

Pls say this a doubt i have

Physics

1 answer:

hodyreva [135]2 years ago

4 0

Question four bulbs A,B,C and D are connected in a circuit shown in the figure below, the letters X, Y and Z represent three switches. Which switch is used to operate switch A separately?
Answer: x

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the average power of the Sun is 3.79x1026 Watts, answer the following questions: 13. What is the average intensity of light at E

Lemur [1.5K]

Explanation:

Given that,

Average power of sun $P=3.79\times10^{26}\ Watt$

We need to calculate the intensity of light at Earth's position

Using formula of intensity

$I=\dfrac{P_{avg}}{4\pi r^2}$

Where, I = intensity

P = power

Put the value into the formula

$I=\dfrac{3.79\times10^{26}}{4\pi\times(1.496\times10^{11})^2}$

$I=1347.616\ W/m^2$

So, The intensity is 1347.616 W/m².

(A). We need to calculate the pressure on a solar sail due to the light of the sun if it's fully reflective

Using formula for fully reflective

$P = \dfrac{2I}{c}$

Put the value into the formula

$P=\dfrac{2\times1347.616}{3\times10^{8}}$

$P=8.984\times10^{-6}\ N/m$

(B). We need to calculate the pressure on a solar sail due to the light of the sun if it's fully reflective

Using formula for fully absorptive

$P=\dfrac{I}{c}$

$P=\dfrac{1347.616}{3\times10^{8}}$

$P=4.492\times10^{-6}\ N/m$

Hence, This is the required solution.

6 0

3 years ago

If earth had no atmosphere, would a falling object ever reach terminal velocity?

stepan [7]

No, because terminal velocity is when the acceleration of the Earth’s gravity is balanced by the air resistance of the atmosphere.

5 0

3 years ago

Which of the following statements correctly describes the models put forth by Ptolemy and Copernicus to explain the universe? A.

FrozenT [24]

The correct option is D.
The model developed by Ptolemy has a lot of inconsistency and during the middle age additional explanation was offered for the claims made by the model. The model was very complicated because it was based on erroneous assumptions.
Copernicus model was simpler and some of his claims were correct.<span />

8 0

3 years ago

Read 2 more answers

Explain what a concentration gradient is and what it means for a molecule to diffuse down its

MArishka [77]

Answer:

Diffusing the gradient ensures that most of the molecules in high concentration zone will wind up in the previously low concentration by the spontaneous movement of small molecules.

Explanation:

A gradient of concentration is the difference between in concentration of one place / area substance to different area. Having a molecule flow down its concentration gradient means moving the molecules from hypotonic areas to the concentration hypertonic areas

Diffusing the gradient ensures that most of the molecules in high concentration zone will wind up in the previously low concentration by the spontaneous movement of small molecules.

7 0

3 years ago

A solid cylinder of mass M = 45 kg, radius R = 0.44 m and uniform density is pivoted on a frictionless axle coaxial with its sym

user100 [1]

Answer:

w_f = 1.0345 rad/s

Explanation:

Given:

- The mass of the solid cylinder M = 45 kg

- Radius of the cylinder R = 0.44 m

- The mass of the particle m = 3.6 kg

- The initial speed of cylinder w_i = 0 rad/s

- The initial speed of particle V_pi = 3.3 m/s

- Mass moment of inertia of cylinder I_c = 0.5*M*R^2

- Mass moment of inertia of a particle around an axis I_p = mR^2

Find:

- What is the magnitude of its angular velocity after the collision?

Solution:

- Consider the mass and the cylinder as a system. We will apply the conservation of angular momentum on the system.

L_i = L_f

- Initially, the particle is at edge at a distance R from center of cylinder axis with a velocity V_pi = 3.3 m/s contributing to the initial angular momentum of the system by:

L_(p,i) = m*V_pi*R

L_(p,i) = 3.6*3.3*0.44

L_(p,i) = 5.2272 kgm^2 /s

- While the cylinder was initially stationary w_i = 0:

L_(c,i) = I*w_i

L_(c,i) = 0.5*M*R^2*0

L_(c,i) = 0 kgm^2 /s

The initial momentum of the system is L_i:

L_i = L_(p,i) + L_(c,i)

L_i = 5.2272 + 0

L_i = 5.2272 kg-m^2/s

- After, the particle attaches itself to the cylinder, the mass and its distribution around the axis has been disturbed - requires an equivalent Inertia for the entire one body I_equivalent. The final angular momentum of the particle is as follows:

L_(p,f) = I_p*w_f

- Similarly, for the cylinder:

L_(c,f) = I_c*w_f

- Note, the final angular velocity w_f are same for both particle and cylinder. Every particle on a singular incompressible (rigid) body rotates at the same angular velocity around a fixed axis.

L_f = L_(p,f) + L_(c,f)

L_f = I_p*w_f + I_c*w_f

L_f = w_f*(I_p + I_c)

-Where, I_p + I_c is the new inertia for the entire body = I_equivalent that we discussed above. This could have been determined by the superposition principle as long as the axis of rotations are same for individual bodies or parallel axis theorem would have been applied for dissimilar axes.

L_i = L_f

5.2272 = w_f*(I_p + I_c)

w_f = 5.2272/ R^2*(m + 0.5M)

Plug in values:

w_f = 5.2272/ 0.44^2*(3.6 + 0.5*45)

w_f = 5.2272/ 5.05296

w_f = 1.0345 rad/s

5 0

3 years ago