Please help me with #6!

What can cause the formation of a magnetic domain?

andrey2020 [161]

Answer:

it is c,d that what I think

3 0

3 years ago

Read 2 more answers

"A trooper is moving due south along the freeway at a speed of 28 m/s. At time t = 0, a red car passes the trooper. The red car

irina1246 [14]

Answer:

24.83 m

Explanation:

Applying the equation of motion;

d = vt + 0.5at^2 ......1

Where;

d = distance

v = velocity

t = time

a = acceleration

For the trooper;

v = 28 m/s

a = 2.9 m/s^2

Substituting into equation 1;

d1 = 28t + 0.5(2.9t^2)

d1 = 28t + 1.45t^2

For the red car;

v = 40 m/s

a = 0

Substituting into equation 1

d2 = 40t

The difference in distance is;

d = d2 - d1

d = 40t - (28t + 1.45t^2)

d = 12t - 1.45t^2

The maximum distance is at d(d)/dt = 0

differentiating d;

d' = 12 - 2.9t = 0

2.9t = 12

t = 12/2.9 = 4.137931034482

t = 4.138 s

Substituting t into function d;

d(max) = 12(4.138) - 1.45(4.138^2)

d(max) = 24.8275862 = 24.83 m

the maximum distance ahead of the trooper that is reached by the red car is 24.83 m

7 0

3 years ago

What is a name given to the areas of an atom where electrons are found?

mestny [16]

Answer:

Shells and Shapes Electrons are found in clouds

Explanation:

3 0

3 years ago

Two sections, A and B, are 0.5 km apart along a 0.05 m diameter rough concrete pipe. A is 115 m higher than B, the water tempera

KonstantinChe [14]

Answer:

Q = 178.41 m^3 / s

Explanation:

Given:

Length of the pipe L = 0.5 km
Diameter D = 0.05 m
Pressure head @ A (P_a / γ )= 21.7 m
Pressure head @ B (P_b / γ )= 76.1 m
Elevation head Z_a = 115 m
Elevation head Z_b = 0 m
Minor Losses = 0 m
Major Losses = f*L*V^2 / 2*D*g = (500/2*0.05*9.81) *f*V^2 = 509.684*f*V^2
Velocity at cross section A and B: V_a = V_b m/s
Roughness e = 2.5 mm
Dynamic viscosity of water u = 8.9*10^-4 Pa-s
Density of water p = 997 kg/m^3

Find:

Flow Rate Q = pi*V*D^2/4 m^3/s ??

Solution:

We will use the Head Balance as derived from Energy Balance:

(P_a / γ ) - (P_b / γ ) + (V_a^2 - V_b^2) / 2*g + (Z_a - Z_b) = Major Losses

21.7 - 76.1 + 0 + 115-0 = 509.684*f*V^2

f*V^2 = 0.18897199

To find correction factor f which is a function of e / D = 0.05, and Reynold's number which is unknown. In such cases we will guess a value of f and perform iterations as follows:

Guess: f_o = 0.072 (Moody's Chart @ e / D = 0.05 and most turbulent function).

V_o = sqrt(0.18897199 / 0.072) = 1.28504 m/s

Re_o = p*V_o*D / u = 997*1.28504*0.05 / 8.9*10^-4 = 71976.6

1st iteration

f_1 = g (Re_o , e/d) = 0.0718702 (Moody's Chart)

V_1 = sqrt(0.18897199 / 0.0718702) = 1.621528 m/s

Re_1 = p*V_1*D / u = 997*1.621528*0.05 / 8.9*10^-4 = 90823.81698

2nd iteration

f_2 = g (Re_1 , e/d) = 0.0718041 (Moody's Chart)

V_2 = sqrt(0.18897199 / 0.0718041) = 1.662273585 m/s

Re_2 = p*V_2*D / u = 997*1.662273585*0.05 / 8.9*10^-4 = 90865.54854

3rd iteration

f_3 = g (Re_2 , e/d) = 0.0718040 (Moody's Chart)

V_3 = sqrt(0.18897199 / 0.0718040) = 1.622274714 m/s

Re_3 = p*V_3*D / u = 997*1.622274714*0.05 / 8.9*10^-4 = 90865.61182

We can observe the convergence of V to 1.6222 m /s. Hence, the required velocity will be used to calculate the Flow rate Q:

Q = pi*V*D^2/4 = pi*1.6222*0.05^2 / 4

Q = 178.41 m^3 / s

3 0

3 years ago

You are 1.8 m tall and stand 2.8 m from a plane mirror that extends vertically upward from the floor. on the floor 1 m in front

velikii [3]

This problem must be solved using a sketch. I attached an illustration of the problem.
You must trace the ray that reflects from the top off the table to your eyes. This how eyesight works, light rays reflects off the objects into your eyes.
Law of reflection tells us that light ray reflects off the surface at the same angle in which it falls on it( i attached another illustration of this).
Now we can write tangens equations:
$tan(\theta)=\frac{h-0.8}{1}\\
tan(\theta)=\frac{1.8-h}{2.8}\\
\frac{h-0.8}{1}=\frac{1.8-h}{2.8}$
We solve for h:
$\frac{h-0.8}{1}=\frac{1.8-h}{2.8}\\
2.8h-0.8\cdot 2.8=1.8-h\\
3.8h=1.8+2.24\\
h=\frac{4.04}{3.8}\\
h=1.06m$

6 0

3 years ago