An imaginary star is four light years from earth. The star has a planet, upon which a large mirror has been installed. The mirror faces earth. A ten year old boy aims his telescope at the mirror. How old will the boy be when he sees his own reflection?

Answer:

increase

Explanation:

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Answer

A.Increses

Explanation:

Answer:

option b is correct..................

The dimension of a/b where x is the distance and t is the time is T

Given the expression

x = at + bt²

where

x is the distance

t is the time

Based on the homogeneity principle, the expression on the left-hand side must be equal to that on the right. Hence;

x = at

[tex]a = \frac{x}{t}[/tex]

Since x is the distance and distance is measured in metres, the dimension equivalent will be the length 'L'

Since t is the time and time is measured in seconds, the dimension equivalent will be the seconds 'T'

[tex]a=\frac{L}{T}[/tex]

Similarly;

x  = bt²

[tex]b=\frac{x}{t^2}\\b=\frac{L}{T^2}[/tex]

Next is to get a/b;

[tex]\frac{a}{b} = \frac{L}{T} \div \frac{L}{T^2}\\\frac{a}{b} = \frac{L}{T}*\frac{T^2}{L} \\\frac{a}{b} =\frac{T^2}{T}\\\frac{a}{b} =T[/tex]

Hence the dimension of a/b is T

One of the scientist's jobs is to report the results of his experiments to all the other scientists in the world.

There isn't a single real science shop anywhere in the world that uses the US customary system of units. Not one.

Even in the measly three countries that use it for measuring carpet, pumping gas, and weighing fish ... Myanmar, Liberia, an the USA ... the scientists do their work in the SI/MKS/metric system.

Answer:

88 m ^2

Explanation:

Answer:

option C

Explanation:

Final velocity of the object is 114 m / s. Hence, final velocity of the object is 114 m / s.

Supplied energy=300kJ

Used energy:-

[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]

We know

[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]

[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]

[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]

[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]

The overall efficiency of the electric car = 76.5 %

To find the efficiency the given values are:

Energy supplied = 300 kJ

Energy wasted = 70.5 kJ

      In the system the output energy is compared to the input energy is known as efficiency. That can be written as percentage ratio of output energy to the input energy.

Formula of efficiency is,

             Efficiency = ( E out / E in ) × 100

Here, Energy supplied = 300 kJ

so, energy used = Energy supplied - Energy wasted

                           = 300 - 70.5

                           =  229.5 kJ

Thus, substituting E out = 300 kJ , E in = 229.5 kJ

            Efficiency = ( 229.5 / 300 ) ×100

                             = 229.5 / 3

                             = 76.5

Hence, The overall efficiency of the electric car is 76.5 %

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We have that the time, to the nearest minute, when the water level is at 1.125 m for the second time after midnight is

[tex]t=10.0hours[/tex]

From the Question we are told that

Maximum height [tex]h_{max}=3m[/tex]

Minimum height  [tex]H_{min}=0.5m[/tex]

Time for  next high tide will occur[tex]T=12 hours =>720 min[/tex]

Generally Average Height

[tex]h_{avg}=\frac{3+0.5}{2}\\\\h_{avg}=1.75[/tex]

Therefore determine Amplitude to be

[tex]A=h_{max}=j_{avg}\\\\A=3-1.75\\\\A=1.25[/tex]

Generally, the equation for Time is mathematically given by

At t=0

[tex]h(x)=Acos(Bx)+h_{avg}[/tex]

Where

[tex]B=\frac{2\pi}{P}\\\\B=\frac{2\pi}{720}\\\\B=8.73*10^{-3}[/tex]

Therefore

[tex]h(t)=Acos8.73*10^{-3}(t)+h_{avg}[/tex]

Hence the Time at [tex]T=1.125[/tex] is

[tex]1.125(t)=1.25cos(8.73*10^{-3})(t)+1.75[/tex]

[tex]-0.1249t=1.75[/tex]

[tex]t=10.0hours[/tex]

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12. C

13. A

14. B

15. D

16. D

17. B

F = m · g

m = 1485 kg

g = 10 N/kg

F = 1485 kg · 10 N/kg = 14 850 N = 14,85 kN

Answer: The weight on Earth is 14,85 kN.

Answer:

Reflection is simply the property of a light that rebounds or bounces back after hitting a surface.

Refraction is when the light, which passes through a surface, undergoes some changes in appearance whenever it usually passes through a medium.

Answer:

78.34

Explanation:

1.3/30=78.3m

Answer:

(a) 11.3 T

(b) 6.09 T

Explanation:

Current, I = 14 kA = 14000 A

number of turns, N = 900

inner radius, r = 0.7 m

outer radius, R = 1.3 m

The magnetic field due to a circular coil is given by

[tex]B = \frac{\mu o}{4\pi}\times \frac{2 N\pi I}{R}[/tex]

(a) The magnetic field due to the inner radius is

[tex]B = 10^{-7}\times \frac{2\times 900\times 3.14\times 14000}{0.7}\\\\B = 11.3 T[/tex]

(b) The magnetic field due to the outer radius is

[tex]B = 10^{-7}\times \frac{2\times 900\times 3.14\times 14000}{1.3}\\\\B = 6.09 T[/tex]

Answer:

334m/s

Explanation:

If you take the data you gave and insert it into the equation f=v/λ the frequency would come out to be 3.34m

334 m/s is  the Velocity of sound in air.

Wave velocity in common usage refers to speed, although, properly, velocity implies both speed and direction.

The velocity of a wave is equal to the product of its wavelength and frequency (number of vibrations per second) and is independent of its intensity.

Mathematically , v=fλ

According to the question,

Sound frequency (f)  = 100Hz

Wavelength (λ)= 3.34m

Computing the values in the formula,

v=fλ

v = 100Hz x 3.34m

v= 334m/s

Therefore,

Velocity of sound in air is 334 m/s.

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Answer:

The right hand rule states that, to find the direction of the magnetic force on a positive moving charge, the thumb of the right hand point in the direction of v, the fingers in the direction of B, and the force (F) is directed perpendicular to the right hand palm.

Explanation:

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Hope this helps u

The vaccine ofcourse. They helped in making the vaccine.

Answer:

The ground hits the ball with same force with which the balls hit the ground. That's why ball bounces back.

Gravity stops it from bouncing forever.

Hope this helps..

Answer:

It's a strength or force

Explanation:

the quantity of motion of a moving body, measured as a product of its mass and velocity

Answer:

momentum is a quality define as the product of the mass and velocity of an object.

Answer:

Numerical Methods are mathematical way to solve certain problems.Whether the equations are linear or nonlinear, efficient and robust numerical methods are required to solve the system of algebraic equations.

Analytical solutions are exact solutions based on mathematical principles.

However, the governing partial differential equations of fluid flow are complex and cannot be solved by analytical means. The partial differential equations are therefore converted into a system of algebraic equations that are subsequently solved through numerical methods to provide approximate solutions to the governing equations.

Although we rarely reach on exact answer , we can get really close to the exact answer much quicker than solve analytically.

Answer:

oh my god

Explanation:

how long answer is this

The points are

(1,10)

(6,0)

[tex]\boxed{\sf slope(m)=\dfrac{y_2-y_1}{x_2-x_1}}[/tex]

[tex]\\ \sf\longmapsto m=\dfrac{0-10}{6-1}[/tex]

[tex]\\ \sf\longmapsto m=\dfrac{-10}{5}[/tex]

[tex]\\ \sf\longmapsto m=-2[/tex]

Answer:

Digestive juices secreted by various organs such as salivary glands in the mouth, stomach, liver and pancreas help in the process of digestion of food. Saliva secreted by the salivary glands in the mouth aids in the breakdown of starch present in the food to simple sugar

Explanation:

Answer:

1.it also hleps us to became doctors becuase without physics you can't be a doctor

2.physics needs to be steady whether you like it or not it helps you in life so everybody must study physics no matter is in Uganda USA and plenty more countries there must be physics to dare to be studied

Answer:

Explanation:

If the mass hangs at the end of the string and the string can support the mass and doesn't break, and the mass hangs still, that means that the tension in the string is equal to the downward pull of the mass. However, we are given the tension in Newtons and the mass needs to be in kg. So we use the equation for weight:

w = mg where w, the weight, is the same as the tension in the string. Gravity is always 9.8 in the metric system:

4.75 = m(9.8) so

m = .48 kg

Answer:

Answer: A

0.485 Kg

Explanation:

Answer:

The speed of the train when the tail buffers pass the lamp post is 9 m/s

Explanation:

The given parameters are;

The length of the train = 90 m

The initial velocity of the train, u = 0

The average acceleration of the train, a = 0.45 m/s²

When the tail buffer pass the lamp post, P, we have;

The distance travelled, s = The length of the train = 90 m

The kinematic equation of motion is given as follows;

v² = u² + 2·a·s

Where;

v = The speed of the train when the tail buffers pass the lamp post

∴ v² = 0² + 2 × 0.45 m/s² × 90 m = 81 m²/s²

Therefore;

v = √(81 m²/s²) = 9 m/s

The speed of the train when the tail buffers pass the lamp post, v = 9 m/s.

Answer:

is that rm in you profile pic

Answer:

CG gh sure er go b vh pxuh FPI OO c AM h kh