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3 years ago

5

A constant power is supplied to a rotating disc .the relationship of angular velocity of disc and number of rotations made by th

e disc is governed by

1 answer:

Bogdan [553]3 years ago

6 0

A rotating disc supplied with constant power where the relationship of the angular velocity of the disc and the number of rotations made by the disc is governed by Newton's second law for rotation. This law is specially made for rotating bodies which is extracted from Newton's second law of motion.

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A horizontal circular wire loop of radius 0.7 m lies in a plane perpendicular to a uniform magnetic field that is pointing down

Maru [420]

Answer:

$\epsilon=1.10\ V$

Explanation:

It is given that,

Radius of the circular loop, r = 0.7 m

Magnetic field, B = 0.44 T

In 0.14 s the wire is reshaped from a circle into a square, but remains in the same plane.

Area of the circular wire,

$A_1=\pi r^2$

$A_1=\pi (0.7)^2=1.539\ m^2$

For the area of square,

The circumference of wire, $C=2\pi r=2\pi \times 0.7=4.39\ m$

Side of square, $l=\dfrac{4.39}{4}=1.09\ m$

Area of square, $A_2=1.09^2=1.188\ m^2$

An emf is induced in the loop due to change in its area. The induced emf is given by :

$\epsilon=-B\dfrac{dA}{dt}$

$\epsilon=-B\dfrac{A_2-A_1}{t}$

$\epsilon=-0.44\times \dfrac{1.188-1.539}{0.14}$

$\epsilon=1.10\ V$

So, the magnitude of the average induced emf is 1.10 volts. Hence, this is the required solution.

3 0

3 years ago

Two particles with masses m and 3m are moving toward each other along the x axis with the same initial speeds Vi. Particle m is

nignag [31]

Answer:

$v1 = \sqrt{(2)}Vi$

$v2 = \sqrt{(2/3)}Vi$

ANGLE is 35.3 degree celcius

Explanation:

Given data:

mass m and 3m

initial speed Vi

particle with mass m is moving toward left while particle with mass 3m is moving toward right

By using conservation of momentum :

$mVi + 3m(-Vi) = mv1 +3mv2$

$-2mVi = m(v1 + 3v2)$

$-2Vi = v1 + 3v2$

conservation of energy :

$m(Vi^2) + 3m(-Vi^2) = mv1^2 + 3mv2^2$

$4mVi^2 = m(v1^2+3v2^2)$

$4Vi^2 = v1^2+3v2^2$

After collision, particle with mass m moves at right angles, thus by considering conservation of momentum in x & y direction,

x direction : $-2mVi = 3m.v2i$

$-2Vi = 3v2i$

y direction : $0 = m(v1)j+3m(v2)j$

$-v1j = 3v2j$

subsitute these value in energy conservation

$v1 = \sqrt{(2)}Vi$

$v2 = \sqrt{(2/3)}Vi$

$angle = tan^{-1}(\frac{\sqrt{(2)}}{2}) =$ 35.3 degree from x-axis

8 0

3 years ago

A relatively small impact crater 20 kilometers in diameter could be made by a comet 2 kilometers in diameter traveling at 25 km/

nadya68 [22]

Answer:

$KE=1.3\times 10^{21}\ J$

$KE=3.1\times 10^{5}\ E$

Explanation:

(a)

Given:

mass of comet, $m=4.2\times 10^{12}\ kg$

velocity of the comet, $v=2.5\times 10^4\ m.s^{-1}$

<u>Now, the kinetic energy of the comet can be given by:</u>

$KE=\frac{1}{2} m.v^2$

$KE=0.5\times 4.2\times 10^{12}\times (2.5\times 10^4)^2$

$KE=1.3\times 10^{21}\ J$

(b)

Given:

energy released by 1 megaton of TNT, $E=4.2\times 10^{15}\ J$

<u>Now the kinetic energy of the comet in terms of energy of 1 megaton TNT:</u>

$KE=\frac{1.3\times 10^{21}}{4.2\times 10^{15}} E$

i.e.

$KE=3.1\times 10^{5}\ E$

4 0

3 years ago

A current-carrying wire is bent into a circular loop of radius R and lies in an xy plane. A uniform external magnetic field B in

Ilya [14]

Answer:

F = 2π I R B

Explanation:

The magnetic force is described by the equation.

F = q v x B = i L x B

Where i is the current, L is a vector that points in the direction of the current (length) and B is the magnetic field.

This equation can be used in scalar form and the direction of the force found by the right hand ruler, the thumb goes in the direction of L, the fingers extended in the direction of B and the palm of the hand indicates the direction of the force if the load is positive

F = i L B sin θ

In this case the wire is in the xy plane and the z-axis field whereby they are perpendicular, θ = 90º and sin 90 = 1

F = i L B

The loop length is

L = 2π R

F = i 2π R B

F = 2π I R B

The force is in the loop

8 0

3 years ago

What does the term conserved mean?

Morgarella [4.7K]

There’s many terms to it

1 : to keep in a safe or sound state He conserved his inheritance. especially : to avoid wasteful or destructive use of conserve natural resources conserve our wildlife. 2 : to preserve with sugar. 3 : to maintain (a quantity) constant during a process of chemical, physical, or evolutionary change conserved DNA ...

4 0

3 years ago