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3 years ago

How are pendulums used in society? Give an example of a real-world pendulum that transfers a lot of energy.

Physics

1 answer:

mart [117]3 years ago

7 0

Answer:

An old clock that has a swinging pendulum

Explanation:

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A fluid is flowing through a circulat tube at 0.4 kg/s. Tube inner surface is smooth with a diameter 0.014 m. Fluid density is 9

ElenaW [278]

Answer:

The convection coefficient is $15456.48\ W/m^{2}K$

Solution:

Mass flow rate, $\dot{m} = 0.4\ kg$

Inner diameter of the tube, d = 0.014 m

Fluid density, $\rho_{f} = 990\ kg/m^{3}$

Specific Heat, C = 3845 J/K

Thermal Conductivity, K = 0.74

Prandtl Number, $P_{r} = 8.6$

Heat flux, $\dot{q} = 71,297\ W/m^{2}$

Viscosity, $\mu = 0.00079\ Ns/m^{2}$

Now,

To calculate the convection heat coefficient, h:

Determine the cross sectional area of the circular tube:

$A_{c} = \frac{\pi}{4}d^{2} = \frac{\pi}{4}\times (0.014)^{2} = 1.54\time 10^{- 4}\ m^{2}$

Determine the velocity of the fluid inside the tube by mass flow rate:

$\dot{m} = \rho_{f}A_{c}v$

$0.4 = 990\times 1.54\time 10^{- 4}v$

v = 2.624 m/s

Determine the Reynold's Number, $R_{e}$ :

$R_{e} = \frac{\rho_{f}dv}{\mu}$

$R_{e} = \frac{990\times 0.014\times 2.624}{0.00079} = 46036.253$

Thus it is clear that $R_{e}$ > 10,000 hence flow is turbulent.

Now,

Determine the Nusselt Number:

$N_{u} = 0.023R_{e}^{0.8}P_{r}^{0.4}$

$N_{u} = 0.023\times 46036.253^{0.8}\times 8.6^{0.4} = 292.42$

Also,

$N_{u} = \frac{dh}{K}$

where

h = convection coefficient

Now,

$292.42 = \frac{0.014\times h}{0.74}$

$h = 15456.48\ W/m^{2}K$

7 0

4 years ago

1. Gwen exerts a 16 N horizontal force as she pulls a 32N sled across a cement

PSYCHO15rus [73]

Answer:

3.6 N Kinetic friction

Explanation:

3 ) Ff = uk * Fn = 3.6 N

5 0

2 years ago

6 An object can never have

MAVERICK [17]

Answer:

Explanation:

Speed is the magnitude of the velocity vector, so it can never be negative.

6 0

3 years ago

A lithium atom has three protons, three neutrons, and three electrons. What is the overall charge on this atom?

Marizza181 [45]

Answer:

Explanation:

The overall charge on this atom is 0.

To find the charge on an atom;

charge = number of protons - number of electrons.

Note:

Protons are the positively charged particles in an atom
Electrons are the negatively charged particles in an atom
Neutrons carries no charges on them.

Since the atom is made up of equal number of protons and electrons, the charge on it is 0.

If the number of electrons is more, the atom will be negatively charge but if the number of protons is more, it will be positively charged.

8 0

3 years ago

Read 2 more answers

A circular loop of wire of cross-sectional area 0.12 m2 consists of 200 turns, each carrying 0.50 A. It is placed in a magnetic

defon

Answer:

0.52 Nm

Explanation:

A = 0.12 m^2, N = 200, i = 0.5 A, B = 0.050 T

Angle between the plane of loop and magnetic field = 30 Degree

Angle between the normal of loop and the magnetic field = 90 - 30 = 60 degree

θ = 60°

Torque = N i A B Sinθ

Torque = 200 x 0.5 x 0.12 x 0.050 x Sin 60

Torque = 0.52 Nm

4 0

3 years ago