Nitrogen oxides in car exhaust react with sunlight to produce

Does coefficient of thermal expansion vary with temperature?

N76 [4]

Answer:

yes

Explanation:

8 0

3 years ago

Please answer ASAP for brainliest

OlgaM077 [116]

Answer:

Question #1- Scientists agree to a standard way of reporting measured quantities in which the number of reported digits reflects the precision in the measurement- more digits, more precision; less digits, less precision. You just studied 14 terms!

Question #2- Units are important because without proper measurement and units to express them, we can never express physical laws precisely just from qualitative reasoning. Units are incredibly important to physics. Two of the most important reasons are the following: (1) they help us. to avoid making mistakes in computation, and (2) they serve as a check on computations once they are completed. In the first case, you can avoid adding 3m and 25cm and coming up with the wrong answer.

Explanation: Hope this helps please mark brainliest!

4 0

3 years ago

Read 2 more answers

In an RC circuit, what fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for

4vir4ik [10]

Answer:

The fraction fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants is

$k = 0.903$

Explanation:

From the question we are told that

The time constant $\tau = 3$

The potential across the capacitor can be mathematically represented as

$V = V_o (1 - e^{- \tau})$

Where $V_o$ is the voltage of the capacitor when it is fully charged

So at $\tau = 3$

$V = V_o (1 - e^{- 3})$

$V = 0.950213 V_o$

Generally energy stored in a capacitor is mathematically represented as

$E = \frac{1}{2 } * C * V ^2$

In this equation the energy stored is directly proportional to the the square of the potential across the capacitor

Now since capacitance is constant at $\tau = 3$

The energy stored can be evaluated at as

$V^2 = (0.950213 V_o )^2$

$V^2 = 0.903 V_o ^2$

Hence the fraction of the energy stored in an initially uncharged capacitor is

$k = 0.903$

4 0

3 years ago

A circular cross section, d = 25 mm, experiences a torque load, T = 25 N·m, and a shear force, V = 85 kN. Calculate the shear st

Maru [420]

Answer:

The correct answer is 231 Mpa i.e option a.

Explanation:

using the equation of torsion we Have

$\frac{T}{I_{p}}=\frac{\tau }{r}\\\\\therefore \tau =\frac{T}{I_{p}}\times r$

where,

$\tau$ = shear stress at a distance 'r' from the center

T = is the applied torque

$I_{p}$ = polar moment of inertia of the section

r = radial distance from the center

Thus we can see that if a point is located at center i.e r = 0 there will be no shearing stresses at the center due to torque.

We know that in case of a circular section the maximum shearing stresses due to a shear force occurs at the center and equals

$\tau _{max}=\frac{4}{3}\times \frac{V}{A}$

Applying values we get

$\tau _{max}=\frac{4}{3}\times \frac{85\times 10^{3}}{0.25\times \pi \times (25\times 10^{-3})^{2}}\\\\\therefore \tau _{max}=230.88Mpa\approx 231Mpa$

3 0

3 years ago

How will frost on the wings of an airplane affect takeoff performance?

san4es73 [151]

Frost will disturb the smooth flow of air over the wing, unpleasantly distressing its lifting competence. In other words, this spoils the even flow of air over the wings, by this means decreasing lifting capability. Also, frost may avoid the airplane from becoming flying at normal departure speed.

8 0

3 years ago