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3 years ago

We are usually not aware of the electric force acting between two everyday objects because

Physics

2 answers:

Semmy [17]3 years ago

5 0

Most everyday objects have as many plus charges as they have minus charges

Hunter-Best [27]3 years ago

4 0

Answer:

Electric force of attraction or repulsion acts between two charged objects. It is a non-contact force. It means the objects need not be in contact for an electric force to exist.

Electric force depends on the amount of charge on each object and distance between them.

We are usually not aware of the electric force acting between two everyday objects because they are neutral in nature that is there are equal number electrons and protons in the atom constituting the objects. Also, with increase in distance, the magnitude of the electric force decreases.

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Is the force of gravity stronger on a piece of crumpled paper or a normal piece of flat paper?

GaryK [48]

Yes, because a crumpled piece of paper has more center mass, allowing it to fall faster.

3 0

3 years ago

If two cars A and B are moving with velocity 60 km/hr and 80 km/hr

Vitek1552 [10]

Answer:

VAB = 20km/hr

Explanation:

<u>Given the following data;</u>

Velocity of car A, VA = 60km/hr

Velocity of car B, VB = 80km/hr

To find the relative velocity of B w.r.t A, VAB;

Since the two cars are moving in the same direction, we have;

VAB = VB - VA

Substituting into the equation, we have;

VAB = 80 - 60

Therefore, the relative velocity of car B with respect to car A is 20 kilometers per hour.

3 0

3 years ago

Find the shear stress and the thickness of the boundary layer (a) at the center and (b) at the trailing edge of a smooth flat pl

melomori [17]

Answer:

a) The shear stress is 0.012

b) The shear stress is 0.0082

c) The total friction drag is 0.329 lbf

Explanation:

Given by the problem:

Length y plate = 2 ft

Width y plate = 10 ft

p = density = 1.938 slug/ft³

v = kinematic viscosity = 1.217x10⁻⁵ft²/s

Absolute viscosity = 2.359x10⁻⁵lbfs/ft²

a) The Reynold number is equal to:

$Re=\frac{1*3}{1.217x10^{-5} } =246507, laminar$

The boundary layer thickness is equal to:

$\delta=\frac{4.91*1}{Re^{0.5} } =\frac{4.91*1}{246507^{0.5} } =0.0098$ ft

The shear stress is equal to:

$\tau=0.332(\frac{2.359x10^{-5}*3 }{1} )(246507)^{0.5} =0.012$

b) If the railing edge is 2 ft, the Reynold number is:

$Re=\frac{2*3}{1.215x10^{-5} } =493015.6,laminar$

The boundary layer is equal to:

$\delta=\frac{4.91*2}{493015.6^{0.5} } =0.000019ft$

The sear stress is equal to:

$\tau=0.332(\frac{2.359x10^{-5}*3 }{2} )(493015.6^{0.5} )=0.0082$

c) The drag coefficient is equal to:

$C=\frac{1.328}{\sqrt{Re} } =\frac{1.328}{\sqrt{493015.6} } ==0.0019$

The friction drag is equal to:

$F=Cp\frac{v^{2} }{2} wL=0.0019*1.938*(\frac{3^{2} }{2} )(10*2)=0.329lbf$

7 0

2 years ago

whats an isotope? give the number of protons, neutrons, and electrons in a neutral atom of each of the following isotopes, Carbo

melamori03 [73]

Isotopes refer to different atoms of the same element (i.e. same number of protons) that differ in the number of neutrons they have (giving them different atomic weights). Atomic weight is the sum of protons and neutrons (each contributes 1 atomic mass unit).

Carbon has 6 protons by definition. If you have a carbon-13 atom (the 13 referring to its mass), the atom has 13 - 6 = 7 neutrons. Since it's neutral, protons = electrons, so there are also 6 electrons.

Sulfur has 16 protons by definition. If you have a sulfur-32 atom, the atom has 32 - 16 = 16 neutrons. Since it's neutral, protons = electrons, so there are also 16 electrons.

8 0

3 years ago

You are running at a speed of 10km/h and hit a patch of mud. Two seconds later you speed is 8km/h. What is your acceleration in

Vlad1618 [11]

Answer:

$0.28 m/s^2$