What is light? A chronology of the concept of light.
This is our timeline.We hope you like it!
lunes, 9 de diciembre de 2013
jueves, 7 de noviembre de 2013
WHAT ARE WAVES?
1. What are waves?
Waves are disturbances that transport energy for one location to another without transportation of matter
2. What are mechanical waves?
Waves that require a medium to propagate from one point to another
3. Why can waves propagate?
Mechanical waves can propagate because of the interaction forces between particles of a medium
4. in the "spring model" what do the springs represent?
Represent the interaction forces between particles.
5. Can you specify two different types of mechanicals waves?
Transverse Waves and Longitudinal Waves
6. Can you define both kinds of waves?
Longitudinal waves make the particles vibrate parallel to the direction of the wave motion; and transverse waves make the particles vibrate perpendicular to the direction of the wave motion.
7. What is "inertia"?
Inertia is the tendency of objects to resist change in motion when pushed or pulled.
8. What kind of particles tend to have more inertia?
Particles which have more inertia are those with more mass.
9. In longitudinal waves, are the particles of the medium carried along by the propagating waves?
The particles of the medium aren’t carried along by the propagating waves because each particle moves left and right in succession as the waves propagate.
10. In longitudinal waves, why don't the particles of the medium move at the same time?
Because the inertia makes particles move in succession and not at the same time.
Waves are disturbances that transport energy for one location to another without transportation of matter
2. What are mechanical waves?
Waves that require a medium to propagate from one point to another
3. Why can waves propagate?
Mechanical waves can propagate because of the interaction forces between particles of a medium
4. in the "spring model" what do the springs represent?
Represent the interaction forces between particles.
5. Can you specify two different types of mechanicals waves?
Transverse Waves and Longitudinal Waves
6. Can you define both kinds of waves?
Longitudinal waves make the particles vibrate parallel to the direction of the wave motion; and transverse waves make the particles vibrate perpendicular to the direction of the wave motion.
7. What is "inertia"?
Inertia is the tendency of objects to resist change in motion when pushed or pulled.
8. What kind of particles tend to have more inertia?
Particles which have more inertia are those with more mass.
9. In longitudinal waves, are the particles of the medium carried along by the propagating waves?
The particles of the medium aren’t carried along by the propagating waves because each particle moves left and right in succession as the waves propagate.
10. In longitudinal waves, why don't the particles of the medium move at the same time?
Because the inertia makes particles move in succession and not at the same time.
lunes, 4 de noviembre de 2013
MATHS EXERCISES
On this exercise we will explain 3 of the exercises we made some time ago on a math exam. For that we will explain these one by one and then solve the exercises.
1- Round these numbers to their tenths
To solve this exercise we must round some decimal numbers to their tenths. To solve these exercises we must look to hundredths and if this is greater or equal to five we will increase the tenth in one.
Let's take as example the first exercise:
a) 6,27 In this case the hundredth number is 7 that is greater than 5. For this reason we will increase the tenth (2) by one. The result of this exercise will be: 6,3
And now, let's solve all the exercises:
b) 3,84 Here, the hundredth (4) is lower than 5, so the tenth will stay as it is (8): 3,8
c) 2,99 Here, the hundredth (9) is greater than 5, so the tenth (9) will be increased by 1, and that will affect the units that will be increased by 1 as well, so the result is: 3
d) 0,094 here the hundredth (9) is greater than 5, so the tenth (0) will be increased by 1: 0,1
e) 0,852 here the hundredth (5) is equal than 5, so the tenth (8) will be increased by 1: 0,9
2- Reduce to one power On this exercise we must solve some powers problems and reduce them to just one power. For that we must know first some things:
Any number raised to the power of one equals the number itself (a^1=a) Any number raised to the power of zero, except zero, equals one (a^0=1 )
When multiplying two powers with the same base, we can simply add the exponents (a^b • a^c = a^b+c)
When dividing two powers with the same base, we can simply substract the exponents (a^b : a^c = a^b-c)
To raise a power to a power, keep the base and multiply the exponents. ((x^m)^n = x^m•n)
Knowing this basic rules we will solve some exercises:
a) 10^5 : 10^2 Here we have a division, so we will take the exponents and make a substraction, so: 10^5 : 10^2 = 10^5-2 = 10^3
b) 10^4 • 10^2 Here we have a multiplication so we will add the exponents, and then we will have: 10^4 • 10^2 = 10^4+2 = 10^6
c) a^4 • a^6 Here we will follow the same base than in the previous exercise so: a^4 • a^6 = a^4+6 = a^10
d) m^2•m^4•m^5 We will continue with the same base, we will add the exponents: m^2•m^4•m^5 = m^2+4+5 = m^11
e) (10^3)^3 Here we must multiply the exponents so: (10^3)^3 = 10^3•3 = 10^9 f) k^6 : k^2 Here we must substract the exponents: k^6 : k^2 = k^6-2 = k^4
3- Greatest Common Divisor The greatest common divisor is the way to operate different fractions, for that we will reduce the divisors to their factors.
a)3 + 5 + 4/7 + 3/4 here 3 and 5 are equal to 3/1 and 5/1 so the Common Divisor will be (7 • 4 (2^2) • 1) and we will multiply the factors by the new numbers so: ((3 • 28)/28) + ((5 • 28)/28) + ((4 • 4)/28) + ((3 • 7)/28) = 84/28 + 140/28 + 16/28 + 21/28 = 261/28
b) 5(3/4) here we have a multiply for that we will multiply the factors with the factors and the divisor with the divisors, so we have: 5/1 • 3/4 = 5•3 / 1•4 = 15/4
c)7/5 : 3/8 Here we will multiply the first factor with the second divisor and it will be the solution factor, and the first divisor with the second factor and it will be the solution divisor so: 7/5 : 3/8 = 7•8/5•3 = 56/15
d)(7/5)^3 We must expose the factor and the divisor so: (7/5)^3 = 7^3/5^3
a) 6,27 In this case the hundredth number is 7 that is greater than 5. For this reason we will increase the tenth (2) by one. The result of this exercise will be: 6,3
And now, let's solve all the exercises:
b) 3,84 Here, the hundredth (4) is lower than 5, so the tenth will stay as it is (8): 3,8
c) 2,99 Here, the hundredth (9) is greater than 5, so the tenth (9) will be increased by 1, and that will affect the units that will be increased by 1 as well, so the result is: 3
d) 0,094 here the hundredth (9) is greater than 5, so the tenth (0) will be increased by 1: 0,1
e) 0,852 here the hundredth (5) is equal than 5, so the tenth (8) will be increased by 1: 0,9
2- Reduce to one power On this exercise we must solve some powers problems and reduce them to just one power. For that we must know first some things:
Any number raised to the power of one equals the number itself (a^1=a) Any number raised to the power of zero, except zero, equals one (a^0=1 )
When multiplying two powers with the same base, we can simply add the exponents (a^b • a^c = a^b+c)
When dividing two powers with the same base, we can simply substract the exponents (a^b : a^c = a^b-c)
To raise a power to a power, keep the base and multiply the exponents. ((x^m)^n = x^m•n)
Knowing this basic rules we will solve some exercises:
a) 10^5 : 10^2 Here we have a division, so we will take the exponents and make a substraction, so: 10^5 : 10^2 = 10^5-2 = 10^3
b) 10^4 • 10^2 Here we have a multiplication so we will add the exponents, and then we will have: 10^4 • 10^2 = 10^4+2 = 10^6
c) a^4 • a^6 Here we will follow the same base than in the previous exercise so: a^4 • a^6 = a^4+6 = a^10
d) m^2•m^4•m^5 We will continue with the same base, we will add the exponents: m^2•m^4•m^5 = m^2+4+5 = m^11
e) (10^3)^3 Here we must multiply the exponents so: (10^3)^3 = 10^3•3 = 10^9 f) k^6 : k^2 Here we must substract the exponents: k^6 : k^2 = k^6-2 = k^4
3- Greatest Common Divisor The greatest common divisor is the way to operate different fractions, for that we will reduce the divisors to their factors.
a)3 + 5 + 4/7 + 3/4 here 3 and 5 are equal to 3/1 and 5/1 so the Common Divisor will be (7 • 4 (2^2) • 1) and we will multiply the factors by the new numbers so: ((3 • 28)/28) + ((5 • 28)/28) + ((4 • 4)/28) + ((3 • 7)/28) = 84/28 + 140/28 + 16/28 + 21/28 = 261/28
b) 5(3/4) here we have a multiply for that we will multiply the factors with the factors and the divisor with the divisors, so we have: 5/1 • 3/4 = 5•3 / 1•4 = 15/4
c)7/5 : 3/8 Here we will multiply the first factor with the second divisor and it will be the solution factor, and the first divisor with the second factor and it will be the solution divisor so: 7/5 : 3/8 = 7•8/5•3 = 56/15
d)(7/5)^3 We must expose the factor and the divisor so: (7/5)^3 = 7^3/5^3
¿Who is Eugene?
Last time we had a guest in our class. He was Eugene, he explained some
things about himself. We asked him about him, about his life, his likes, his
studies...
He has 23 years old. We found out that he was born in Russia but he life in Brooklyn, New York. He studied anthropology and foreign languages.
He learned to play the piano too for seven years. But, he don't play it anymore. He said that, ''I didn't want to play the piano, but my parents wanted it, so I had to learn to''. play it because They are classical musicians.
Eugene is a dancer. His favourite dancing style is Latin American ballroom dance. He loves dancing, however, he don't give dance lessons yet.
Eugene have three tattoos and he explained to us the meaning. The last thing he got tattooed is a balance on his neck. He likes contemporary folk and trip hop music.
His favourite groups are Mashrou3, Leila and Soap Kills.
He learned to play the piano too for seven years. But, he don't play it anymore. He said that, ''I didn't want to play the piano, but my parents wanted it, so I had to learn to''. play it because They are classical musicians.
Eugene is a dancer. His favourite dancing style is Latin American ballroom dance. He loves dancing, however, he don't give dance lessons yet.
Eugene have three tattoos and he explained to us the meaning. The last thing he got tattooed is a balance on his neck. He likes contemporary folk and trip hop music.
His favourite groups are Mashrou3, Leila and Soap Kills.
viernes, 25 de octubre de 2013
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