Why is sun called a source of light??

How is velocity and instantaneous speed alike

allsm [11]

<span>velocity is defined as the rate of change of displacement irrespective of the length of the path travelled while speed is the average rate of covering distance. but in the liming case where the instantaneous velocity is given as v=dx/dt where dx is the small displacement in a small interval dt, both the speed and velocity have the same magnitude and the direction of velocity is the direction of the tangent to the corresponding displacement-time curve.</span>

5 0

2 years ago

A specimen of steel has a rectangular cross section 20 mm wide and 40 mm thick, an elastic modulus of 207 GPa, and a Poisson’s r

katrin2010 [14]

Answer:

There's a decrease in width of 2.18 × 10^(-6) m

Explanation:

We are given;

Shear Modulus;E = 207 GPa = 207 × 10^(9) N/m²

Force;F = 60000 N.

Poisson’s ratio; υ =0.30

We are told width is 20 mm and thickness 40 mm.

Thus;

Area = 20 × 10^(-3) × 40 × 10^(-3)

Area = 8 × 10^(-4) m²

Now formula for shear modulus is;

E = σ/ε_z

Where σ is stress given by the formula Force(F)/Area(A)

While ε_z is longitudinal strain.

Thus;

E = (F/A)/ε_z

ε_z = (F/A)/E

ε_z = (60,000/(8 × 10^(-4)))/(207 × 10^(9))

ε_z = 3.62 × 10^(-4)

Now, formula for lateral strain is;

ε_x = - υ × ε_z

ε_x = -0.3 × 3.62 × 10^(-4)

ε_x = -1.09 × 10^(-4)

Now, change in width is given by;

Δw = w_o × ε_x

Where w_o is initial width = 20 × 10^(-3) m

So; Δw = 20 × 10^(-3) × -1.09 × 10^(-4)

Δw = -2.18 × 10^(-6) m

Negative means the width decreased.

So there's a decrease in width of 2.18 × 10^(-6) m

6 0

2 years ago

A line _____ on a typical Speed vs. Time graph means an object is experiencing a constant acceleration.

Savatey [412]

Answer:

The answer should be C. slanted upward to the right.

Hope this helps. :-)

7 0

3 years ago

Read 2 more answers

Which statement explains the polarity of a water molecule?

timofeeve [1]

Answer:

D. The oxygen side is partially negative because electrons are pulled toward the oxygen side.

Explanation:

The water molecule is polar by the virtue of covalent bonds and the hydrogen bonds within and between its molecule.

The oxygen side is partially negative because the electrons are pulled toward the oxygen side.

Between oxygen and hydrogen that makes up the water molecule, oxygen is more electronegative.

An electronegative atom has more affinity for electrons. Since the electrons in the molecule of water is shared between hydrogen and oxygen, the more electronegative specie which is water draws the electron more to itself.

This leaves a net negative charge on the oxygen atom.

8 0

2 years ago

A transformer has 1000 turns in the primary coil and 100 turns in the secondary coil. If the primary coil is connected to a 120

alexdok [17]

Answer:

12 V, 0.5 A

Explanation:

For the Voltage,

Using,

Vs/Vp = Ns/Np.......................... Equation 1

Where Vs = Voltage in the secondary coil, Vp = Voltage in the primary coil, Ns = number of turn in the secondary coil, Np = number of turns in the primary coil.

Make Vs the subject of the equation

Vs = Vp(Ns/Np)........................ Equation 2

Given: Vp = 120 v, Np = 1000 turns, Ns = 100 turns

Substitute into equation 2

Vs = 120(100/1000)

Vs = 120×0.1

Vs = 12 v

For the current,

Using

Ns/Np = Ip/Is....................... Equation 3

Where Ip = current in the primary coil, Is = current in the secondary coil

make Is the subject of the equation

Is = Ip(Np/Ns).................. Equation 4

Given: Np = 1000 turns, Ns = 100 turns, Ip = 0.05 A

Substitute into equation 4

Is = 0.05(1000/100)

Is = 0.05×10

Is = 0.5 A.

Hence the voltage and the current in the secondary coil is 12 V, 0.5 A

4 0

2 years ago

Read 2 more answers

Why is sun called a source of light??​

Why is sun called a source of light??