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3 years ago

Explain how to find instantaneous velocity and find it for s(t) = -3 + 4t2 when t = 5 seconds

1 answer:

8 0

Velocity is a vector quantity, that's formally defined as the rate of change of position or displacement with time. When stating any vector like the velocity of an object, we talk about direction, as well as magnitude. That's why speed and velocity are different things. Speed is a scalar (a pure number, specified by magnitude, without direction), while velocity is a vector. To put it simply, speed is the magnitude of the velocity. When talking about velocity, we specify it according to some fixed frame of reference and its unit is meters/second. It can be measured in two ways. One is in the form of average velocity, while the other is instantaneous velocity. The formula for the former is as follows.

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Suppose that the dipole moment associated with an iron atom of an iron bar is 2.8 × 10-23 J/T. Assume that all the atoms in the

masya89 [10]

To solve this exercise it is necessary to apply the equations related to the magnetic moment, that is, the amount of force that an image can exert on the electric currents and the torque that a magnetic field exerts on them.

The diple moment associated with an iron bar is given by,

$\mu = \alpha *N$

Where,

$\alpha =$ Dipole momento associated with an Atom

N = Number of atoms

$\alpha$ y previously given in the problem and its value is 2.8*10^{-23}J/T

$L = 5.8cm = 5.8*10^{-2}m$

$A = 1.5cm^2 = 1.5*10^{-4}m^2$

The number of the atoms N, can be calculated as,

$N = \frac{\rho AL}{M_{mass}}*A_n$

Where

$\rho =$ Density

$M_{mass} =$ Molar Mass

A = Area

L = Length

$A_n =$ Avogadro number

$N = \frac{(7.9g/cm^3)(1.5cm)(5.8cm^2)}{55.9g/mol}(6.022*10^{23}atoms/mol)$

$N = 7.4041*10^{23}atoms$

Then applying the equation about the dipole moment associated with an iron bar we have,

$\mu = \alpha *N$

$\mu = (2.8*10^{-23})*(7.4041*10^{23})$

$\mu = 20.72Am^2$

PART B) With the dipole moment we can now calculate the Torque in the system, which is

$\tau = \mu B sin(90)$

$\tau = (20.72)(2.2)$

$\tau = 45.584N.m$

Note: The angle generated is perpendicular, so it takes 90 ° for the calculation made.

3 0

3 years ago

1.Mention two uses of the concave mirror.

Anuta_ua [19.1K]

Answer:

1. telescope

$f = \frac{r}{2}$

$f = \frac{r}{2}$ f- focal length

$f = \frac{r}{2}$ f- focal length r- the radius of curvature of the mirror

$\frac{1}{f} = \frac{1}{p} + \frac{1}{l}$

p-the distance of the object from the vertex of the mirror

l-the distance of the figure from the vertex of the mirror

8 0

3 years ago

I need the answer to this question what has the student plotted on the vertical axis?

expeople1 [14]

Answer:

The correct option is D

Explanation:

In trying to achieve what the student wanted to see, which is to see the relationship between the weight the cord can hold and how long the cord will stretch. Since the origin of the graph is from zero, the value plotted on the vertical axis would be just the length caused by each weights. Thus, the original length would have to be subtracted from the measured length to determine the actual length caused by the weight added to the cord.

7 0

3 years ago

Atoms in Group 18 elements are inert (chemically unreactive) because ___________________________. A they combined to form molecu

Rom4ik [11]

When you say full valence shell, are you talking about a valence electron shell?

I am learning about atoms and i know a little bit

6 0

3 years ago

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The smallest division value of electronic balance

lara [203]

Answer: