pls,help ASAP .the question is in attachment​

Answer:

The mass of platinum iridium rod whose diameter and height are equal an kept at international bureau of weight and measurement in Paris of France is called as one standard kg.

Answer:

Answer:

The number of turns in the solenoid is 19506.

Explanation:

Length of solenoid, L = 0.28 m

Magnetic field, B = 7 T

Current, I = 80 A

Let the number of turns is N.

The formula used to find the magnetic field is

[tex]B = \frac{\mu 0N I}{L}\\\\7 = \frac{4 \times 3.14\times 10^{-7}\times N\times 80}{0.28}\\\\N = 19506[/tex]

The answer to the digits rounded to one significant figure is 100.

Significant figures are the most important figures in a number of digits.

The closer a digit is to the beginning of a number, the more important  or significant  it is.

But, the rule for rounding up a set of numbers to the first significant or to one significant figure is that:

From the numbers 98.907, 9 is the most significant digit followed by 8.

8 is greater than 5 so we should round up by adding one to 9 making the number 100.

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We know

[tex]\boxed{\sf K.E=\dfrac{1}{2}mv^2}[/tex]

[tex]\\ \sf\longmapsto K.E=\dfrac{1}{2}\times 2\times 40^2[/tex]

[tex]\\ \sf\longmapsto K.E=40^2[/tex]

[tex]\\ \sf\longmapsto K.E=1600J[/tex]

Answer:

It is the inability of the body to change by itself its state of rest or uniform motion or direction. Types of Inertia- It is of three types-(1)Inertia of rest (2) Inertia of motion(3) Inertia of direction. (1) Inertia of rest - It is the inability of the body to change by itself its state if rest.

Answer:

A) The population of prey is greater than that of predator

Answer:

658.2 nm

Explanation:

Since the galaxy is moving at relavitistic speed, we use the equation for relativistic Doppler shift of light.

So, the wavelength of light observed on the Earth is λ

λ = λ'([tex]\sqrt{\frac{ 1 + \frac{v}{c} }{1 - \frac{v}{c} } }[/tex])

where  λ' = wavelength of light emitted by galaxy = 656 nm, v = speed of galaxy = 1000 km/s (positive since the galaxy is moving away from the Earth) and c = speed of light = 300000 km/s

So, substituting the values of the variables into the equation, we have

λ = λ'(√[{1 + (v/c)}/(1 - (v/c)]

λ = 656 nm(√[{1 + (1000 km/s/300000 km/s)}/(1 - (1000 km/s/300000 km/s)]

λ = 656 nm(√[{1 + 1/300}/(1 - 1/300]

λ = 656 nm(√[{(300 + 1)/300}/{(300 - 1)/300}]

λ = 656 nm(√[{(301)/300}/{(299)/300}]

λ = 656 nm(√[301/299])

λ = 656 nm(√1.0067)

λ = 656 nm × 1.0033

λ = 658.19 nm

λ ≅ 658.2 nm

So, the wavelength observed on Earth is 658.2 nm

Answer:

Yes but no

Explanation:

Here the kid cant say that he has created s magnetic field as iron fillings do not have magnetic properties

Answer:V₁=300ml

T₁=27°C

V₂=?

T₂= -3°C

as we know

V₁T₁=V₂T₂

By putting values in formula

300ml×27°C=V₂×(-3°C)

300ml×27°C/-3°C=V₂

8100ml/-3=V₂

-2700ml=V₂

or V₂=  -2700ml

Answer:

Explanation:

As seen, batteries have chemical energy in them stored which when used in any electronics produces electricity.

Thus, we can conclude that a battery converts chemical energy into electric energy.

Answer:

The comparison of unknown quantity with known quantity is called measurement

Answer:

the size, length or amount of something is a measurement.

Explanation:

Measurements help in daily life and are important to development, accuracy and making decisions.

Answer:

may be d)45°

Explanation:

Answer:

Their final relative velocity is 0.190 m/s

Explanation:

The relative velocity of the satellites, v = 0.190 m/s

The mass of the first satellite, m₁ = 4.00 × 10³ kg

The mass of the second satellite, m₂ = 7.50 × 10³ kg

Given that the satellites have elastic collision, we have;

[tex]v_2 = \dfrac{2 \cdot m_1}{m_1 + m_2} \cdot u_1 - \dfrac{m_1 - m_2}{m_1 + m_2} \cdot u_2[/tex]

[tex]v_2 = \dfrac{ m_1 - m_2}{m_1 + m_2} \cdot u_1 + \dfrac{2 \cdot m_2}{m_1 + m_2} \cdot u_2[/tex]

Given that the initial velocities are equal in magnitude, we have;

u₁ = u₂ = v/2

u₁ = u₂ = 0.190 m/s/2 = 0.095 m/s

v₁ and v₂ = The final velocities of the satellites

We get;

[tex]v_1 = \dfrac{2 \times 4.0 \times 10^3}{4.0 \times 10^3 + 7.50 \times 10^3} \times 0.095 - \dfrac{4.0 \times 10^3- 7.50\times 10^3}{4.0 \times 10^3+ 7.50\times 10^3} \times 0.095 = 0.095[/tex]

[tex]v_2 = \dfrac{ 4.0 \times 10^3 - 7.50\times 10^3}{4.0 \times 10^3 + 7.50 \times 10^3} \times 0.095 + \dfrac{2 \times 7.50\times 10^3}{4.0 \times 10^3+ 7.50\times 10^3} \times 0.095 = 0.095[/tex]

The final relative velocity of the satellite, [tex]v_f[/tex] = v₁ + v₂

∴ [tex]v_f[/tex] = 0.095 + 0.095 = 0.190

The final relative velocity of the satellite, [tex]v_f[/tex] = 0.190 m/s

Answer:

Joule

Explanation:

the unit of work is Joule determined by the letter J.

Answer:

Explanation:

Joule is defined as the work done by a force of one newton causing a displacement of one meter. Sometimes, newton-metre (N-m) is also used for measuring work.

Answer:

a. Energy lost, Q = 16,800 Joules.

b. Power = 28 J/s

c. Time, t = 2357.14 seconds

d. I assumed that the ice remained at a temperature of zero degrees Celsius (0°C). Also, I assumed that the heat is being lost at a constant rate.

Explanation:

Given the following data;

a. To find the energy lost by the water as it cools to 0 degree celsius;

Mathematically, heat capacity is given by the formula;

[tex] Q = mcdt [/tex]

Where;

dt = T2 - T1

dt = 20 - 0

dt = 20°C

We know that the specific heat capacity of water is equal to  4200 J/kg°C

Substituting the values into the formula, we have;

[tex] Q = 0.20 * 4200 * 20 [/tex]

Energy lost, Q = 16,800 Joules.

b. To find the average rate at which the water is losing energy in J/s by using the following formula;

[tex] Power = \frac {energy}{time} [/tex]

First of all, we would have to convert the value of time in minutes to seconds.

Conversion:

1 minute = 60 seconds

10 minutes = X seconds

Cross-multiplying, we have;

X = 60 * 10

X = 600 seconds

Substituting the values into the formula, we have;

[tex] Power = \frac {16800}{600} [/tex]

Power = 28 J/s

c. To estimate the time taken for the water at 0 degree celsius to turn completely into ice;

We know that the latent heat of fusion of water is equal to 3.3 * 10⁵ J/kg.

Mathematically, the latent heat of fusion is calculated by using the formula;

Energy, Q = ml = pt

Substituting the values into the formula, we have;

0.20 * 3.3 * 10⁵ = 28 * t

0.20 * 330000 = 28t

66000 = 28t

[tex] t = \frac {66000}{28} [/tex]

Time, t = 2357.14 seconds.

d. The assumption made is that, the ice remained at a temperature of zero degrees Celsius (0°C). Also, I assumed that the heat is being lost at a constant rate.

Answer:

a) 70, 95

b) 95-70= 25cc

c) density= mass/volume

102/25

=4.08g/cc

Answer:

Velocity is the rate of change of displacement.

Answer:

The capacity of an RD bottle is 100cc and its mass is 45g. Find the mass of the bottle when it is filled with a liquid of density 600kg/[tex]m^{3}[/tex]

EXPLANATION:

100cc=100[tex]cm^{3}[/tex]

density of liquid=600Kg/  =0.6gm/

 so mass of 100cc liquid will be m=d×V=0.6×100=60gm

So mass of bottle filled with liquid will be bottle+liquid=45gm+60gm=105gm  

Answer is 105gm.

Answer:

DU = 120 Joules

Explanation:

Given the following data;

Quantity of energy = 200 J

Work = 80 J

To find the change in internal energy;

Mathematically, the change in internal energy of a system is given by the formula;

DU = Q - W

Where;

DU is the change in internal energy.

Q is the quantity of energy.

W is the work done.

Substituting into the formula, we have;

DU = 200 - 80

DU = 120 Joules

Answer:

1. The efficiency of the radiator is 90 %

2. The efficiency of the torch is 65 %

3. The efficiency of the car is 40 %

4. The efficiency of the energy saver is 70 %

5. The efficiency of the speaker is 50 %

Explanation:

Efficiency = (Useful energy out ÷ Total energy in) × 100 J

1. Useful energy = 900 J

The total energy in = 1000 J

The efficiency of the radiator = ((900 J)/(1,000 J)) × 100 % = 90 %

2. Useful energy = 65 J

The total energy in = 100 J

The efficiency of the torch = ((65 J)/(100 J)) × 100 % = 65 %

3. Useful energy = 4,000 J

The total energy in = 10,000 J

The efficiency of the car = ((4,000 J)/(10,000 J)) × 100 % = 40 %

4. Useful energy = 700 J

The total energy in = 1,000 J

The efficiency of the energy saver = ((700 J)/(1,000 J)) × 100 % = 70 %

5. Useful energy = 50 J

The total energy in = 100 J

The efficiency of the speaker = ((50 J)/(100 J)) × 100 % = 50 %

Answer:

simple machine, any of several devices with few or no moving parts that are used to modify motion and the magnitude of a force in order to perform work. ... The simple machines are the inclined plane, lever, wedge, wheel and axle, pulley, and screw.

Answer:  An effect of continental drift is causing tectonic plates resting upon the convecting mantle to move which results in natural disasters like earthquakes, volcanic eruptions, and more.

Answer:

SI unit is an internationally accepted system and have the same value all over the world .

I don't know the importance sotry

Answer:

SI unit is an internationally accepted system that have same value all over the world.

Answer:

C

Explanation:

Answer:

A)

Explanation:

it keeps the electric current flowing in one direction

Answer:

given,

load = 400 N

effort = 100 N

load distance = 20 cm

we know that ,

E*Ed = L*Ld

=100 N* Ed = 400N * 20 cm

=100N * Ed = 8000N/cm

= Ed =( 8000N/cm ) / 100N

= Ed = 80 cm

b. soln.

given,

load = 600 N

load distance = 2 m

effort = 300 N

effort distance = ?

we know that ,

= E *Ed = L * Ld

= 300N * Ed = 600N * 2 m

= 300N * Ed = 1200N/m

=Ed =( 1200N/m ) / 300 N

= Ed = 4 m

C. soln.

given,

load = 600 N

load distance =20 cm

effort = 200 N

effort distance = ?

M.A = ?

V.R = ?

Efficiency = ?

we know that ,

= E *Ed = L *Ld

= 200N * Ed = 600 N * 20 cm

=200 N *Ed = 12000 N/cm

=Ed = ( 12000 N/cm) / 200 N

= Ed = 60 cm

Also,

M.A = load / effort

=600 N / 200 N

= 3

V.R = Ed/ Ld

= 60 cm / 20 cm

= 4

efficiency = ( M.A / V.R ) 100 %

= ( 3 / 4 ) 100%

= 75 %

d. soln.

given,

load = 600 N

load distance = 0.5 m

effort distance = 2.5 m

effort = ?

we know that ,

= E * Ed = L * Ld

= E * 2.5 m = 600 N * 0.5 m

= E * 2.5 m = 300 N / m

= E = ( 300 N / m ) / 2.5 m

= E = 120 N

Answer:

Pressure and velocity are inversely proportional to each other because if pressure increase, the velocity decrease to keep the algebraic sum of potential energy, kinetic energy and pressure constant.