1
00:00:06,900 --> 00:00:13,939
Good morning to you all. I'm going to tell you what you have to do today for Natural Sciences.

2
00:00:14,380 --> 00:00:27,039
Okay, so as usual, everybody clicks on Mi Clase, then we go to Contenido and go to Natural Sciences.

3
00:00:27,039 --> 00:00:38,820
so we're still doing unit 5 forces and we are going to learn about something that you have

4
00:00:38,820 --> 00:00:50,979
heard already because you know about that which is gravity so gravity is a non-contact force

5
00:00:50,979 --> 00:00:58,500
It's a pulling force and it pulls towards the center of the objects, okay?

6
00:00:59,000 --> 00:01:09,500
So it was discovered by Newton and he realized that once he was reading down a tree

7
00:01:09,500 --> 00:01:18,560
and suddenly an apple fell down and smacked his head, all right?

8
00:01:18,560 --> 00:01:33,719
So it was a hundred of years ago and, well, we will read about Newton in a few lessons time.

9
00:01:50,189 --> 00:01:57,150
un día que estaba sentado debajo de un árbol leyendo y le cayó una manzana del

10
00:01:57,150 --> 00:02:03,870
árbol y se puso a pensar sobre eso y entonces empezó a generar su teoría

11
00:02:03,870 --> 00:02:08,849
sobre la gravedad pero bueno ya aprenderemos algo más

12
00:02:08,849 --> 00:02:18,599
sobre newton en el futuro we are going to learn about gravity and weight vamos

13
00:02:18,599 --> 00:02:28,360
escuch vamos a aprender sobre pues una fuerza nueva que es la gravedad y otra fuerza nueva que

14
00:02:28,360 --> 00:02:34,919
también conocemos que es el peso estas dos palabras seguro que las conocéis todos pero

15
00:02:34,919 --> 00:02:44,879
bueno vamos a aprender un poco más que son cada una so what is gravity gravity is a non contact

16
00:02:44,879 --> 00:02:54,900
force and is a pull force. Remember that we knew different ways of classifying forces.

17
00:02:55,620 --> 00:03:03,699
In this case, gravity, we say that is a non-contact and is a pull force. And all objects,

18
00:03:03,699 --> 00:03:12,759
it's not right that all objects have gravity, but all objects are attracted by other objects or

19
00:03:12,759 --> 00:03:20,180
attract other objects, all right? So, as we were saying, it's a non-contact force that

20
00:03:20,180 --> 00:03:30,280
pulls towards the center of objects, all right? This force is noticeable with very large objects,

21
00:03:30,280 --> 00:03:42,099
all right? So, the gravity that we could attract with is very small, while the gravity on Earth

22
00:03:42,099 --> 00:03:52,500
is is very big because the earth is a very big planet and um the gravity is this pulling force

23
00:03:52,500 --> 00:03:59,860
that pulls us towards the center of the earth as you can see with these arrows and this prevents us

24
00:03:59,860 --> 00:04:07,219
from floating away this is the reason we are not floating because when we are in the in the

25
00:04:07,219 --> 00:04:17,939
downside of the the earth nobody is falling down all right so because of gravity we stay on the

26
00:04:17,939 --> 00:04:27,300
ground and we're not floating everything that we throw up it will go down again we cannot leave

27
00:04:27,300 --> 00:04:39,220
very big objects objects with a large mass large mass and the moon orbits the earth instead of

28
00:04:39,220 --> 00:04:45,779
flying away it's it's all the time around us surrounding the earth okay moving around

29
00:04:46,899 --> 00:04:56,019
what happened with the earth and the moon so big objects have a stronger pull towards

30
00:04:56,019 --> 00:05:02,819
their center than smaller objects all right so the bigger the object as i said before

31
00:05:03,860 --> 00:05:14,660
the more gravity so the earth is six times bigger than the moon so obviously it will have more

32
00:05:14,660 --> 00:05:25,300
gravity force than the moon which is six times uh smaller so the gravity will be six times

33
00:05:25,300 --> 00:05:35,899
smaller too, all right? So we can see that the Earth has a gravity of 10, it would be 10 meters

34
00:05:35,899 --> 00:05:45,300
by square second, but you will learn about that in a few years, okay? And in the Moon it's 1.6,

35
00:05:45,300 --> 00:05:55,639
So, obviously, it means that in the moon we would be lighter than on Earth, okay?

36
00:05:55,860 --> 00:06:03,199
So, it says that it could be easier to jump because there is less gravity than on Earth, right?

37
00:06:07,850 --> 00:06:10,290
Bueno, lo cuento en español rápidamente.

38
00:06:10,290 --> 00:06:19,889
gravity is a force without contact and it is a force of grip that all objects have

39
00:06:19,889 --> 00:06:29,930
according to gravity it pulls all objects towards the center of the earth in this case and we can

40
00:06:29,930 --> 00:06:37,689
see the arrows of agreement and that makes us not float and that the people who are

41
00:06:37,689 --> 00:06:42,250
down here does not fall in agreement because we are continuously attracted

42
00:06:42,250 --> 00:06:48,490
by objects gravity says here it is noticeable this means that it is

43
00:06:48,490 --> 00:06:55,430
noticed that it can be perceived in large objects and when we talk about

44
00:06:55,430 --> 00:06:59,870
large objects we are talking about incredibly large objects such as

45
00:06:59,870 --> 00:07:07,569
for example planets agree an object like a building because it also generates

46
00:07:07,569 --> 00:07:13,069
a gravitational attraction force but much smaller so small that

47
00:07:13,069 --> 00:07:19,870
it is that I do not know that it is impossible to perceive it in agreement or that is that when

48
00:07:19,870 --> 00:07:25,089
we are talking about very large of the objects we are talking about massively

49
00:07:25,089 --> 00:07:32,870
large objects of objects that are immense in agreement well because of gravity

50
00:07:32,870 --> 00:07:40,310
due to gravity we stay stuck to the ground and we are not floating due to gravity everything

51
00:07:40,310 --> 00:07:46,790
that we throw into the air falls again or we cannot lift an object with a very large mass and

52
00:07:46,790 --> 00:07:52,790
this mass has stayed with it because we are going to see it now a little later and due to

53
00:07:52,790 --> 00:07:59,689
gravity the moon is orbiting around the earth and it has not yet moved away from the earth

54
00:07:59,689 --> 00:08:07,009
de acuerdo sigue dando vueltas una y otra vez alrededor de la tierra de acuerdo esto es porque

55
00:08:07,009 --> 00:08:14,769
la luna se ve atraída también por la gravedad de la tierra bueno vamos a ver un poco más sobre la

56
00:08:14,769 --> 00:08:24,769
tierra y la luna bueno tenemos que saber que cuanto más grande es el objeto mayor gravedad

57
00:08:24,769 --> 00:08:37,309
generates according to that the earth that is six times larger than the moon generates a gravity that is also

58
00:08:37,309 --> 00:08:46,980
six times larger than that of the moon according to this which means that well we would give the

59
00:08:46,980 --> 00:08:54,480
gravity a value of 10 are 10 meters per second squared is a measure of acceleration but well

60
00:08:54,480 --> 00:09:00,779
this you will see later and the gravity on the moon would be 1.6

61
00:09:00,779 --> 00:09:07,580
agreement when there is less gravity on the moon because what you will have seen happens in

62
00:09:07,580 --> 00:09:14,399
some video surely by youtube or in some documentary that is that people

63
00:09:14,399 --> 00:09:19,919
can move around the moon giving jumps and very long jumps because

64
00:09:19,919 --> 00:09:23,659
Precisamente, la fuerza de la gravedad es mucho menor.

65
00:09:24,659 --> 00:09:26,159
Okay, let's go for the next thing.

66
00:09:26,600 --> 00:09:28,299
Mass and weight.

67
00:09:28,620 --> 00:09:30,059
Mass and weight.

68
00:09:30,059 --> 00:09:36,000
So, it's very important to feel the difference between these two, okay?

69
00:09:36,080 --> 00:09:38,919
Because they are not the same, okay?

70
00:09:39,419 --> 00:09:43,700
Mass is the amount of matter in an object, all right?

71
00:09:43,779 --> 00:09:45,159
It's measured in kilograms.

72
00:09:45,860 --> 00:09:48,360
And weight is another thing, all right?

73
00:09:48,360 --> 00:09:58,539
weight is a force, okay? And it is calculated by multiplying mass by gravity, okay? And it is

74
00:09:58,539 --> 00:10:06,379
measured in newtons, newtons. Remember that we've talked about newton before? So, because of newton,

75
00:10:06,379 --> 00:10:19,779
they decided to name this force, okay? So, as we have to multiply mass by gravity, we can

76
00:10:19,779 --> 00:10:29,039
calculate the weight with different gravities. And look at the example. The dog has a mass of

77
00:10:29,039 --> 00:10:35,879
10 kilograms, all right? 10 kilograms. Its mass is the same on Earth and the Moon because it

78
00:10:35,879 --> 00:10:43,919
doesn't change okay but what changes is the gravity as the gravity changes the

79
00:10:43,919 --> 00:10:54,299
weight the weight would change too all right so the dog that is 10 kilograms on

80
00:10:54,299 --> 00:11:01,860
earth the weight would be calculated multiplying 10 by 10 which is 10 100

81
00:11:01,860 --> 00:11:13,379
newtons, okay? But on the Moon, the mass would be 10 kilos multiplied by 1.6, that gives us

82
00:11:13,379 --> 00:11:24,899
16 newtons. So we can see that the weight on Earth is bigger than the weight on the Moon, okay?

83
00:11:24,899 --> 00:11:33,700
And this is obviously because the gravity on Earth is stronger than the gravity on the moon.

84
00:11:33,700 --> 00:11:37,419
En español, muy rápido. Tenemos la masa y el peso.

85
00:11:38,940 --> 00:11:46,039
Y no tenemos que confundirlos, ¿de acuerdo? Porque esto normalmente se suelen confundir.

86
00:11:46,440 --> 00:11:50,980
La masa es la cantidad de materia que tiene un objeto, ¿de acuerdo?

87
00:11:50,980 --> 00:11:55,299
If an object is bigger, if it is smaller, the amount of mass.

88
00:11:55,879 --> 00:11:57,360
And it is measured in kilograms.

89
00:11:58,299 --> 00:12:00,120
In kilograms, kilograms.

90
00:12:00,279 --> 00:12:02,039
It is the same word in English and in Spanish.

91
00:12:02,620 --> 00:12:04,080
And weight is weight.

92
00:12:04,460 --> 00:12:06,179
And weight is a force.

93
00:12:07,080 --> 00:12:07,419
Okay?

94
00:12:07,960 --> 00:12:10,000
And this force, how is it calculated?

95
00:12:10,000 --> 00:12:15,600
It is calculated by multiplying the mass, which was the amount of matter, by gravity,

96
00:12:15,600 --> 00:12:21,700
which is this force that we had said that it was a non contact pool in force a

97
00:12:21,700 --> 00:12:29,360
gravity was a force without contact of grip of agreement and when we multiply

98
00:12:29,360 --> 00:12:37,100
the mass by gravity we have the weight that is measured in newtons we are going to

99
00:12:37,100 --> 00:12:42,519
understand this easier for example this little dog on earth and on the moon in

100
00:12:42,519 --> 00:12:47,620
both places its mass is 10 kilograms that does not change because the dog is the same

101
00:12:47,620 --> 00:12:54,580
however the weight does change because because while on earth to

102
00:12:54,580 --> 00:12:59,919
calculate the weight we have to multiply the mass which are 10 kilograms by 10

103
00:12:59,919 --> 00:13:05,379
which was the value that we had given to the gravity of the earth because the force

104
00:13:05,379 --> 00:13:10,179
that we would have the weight that we would have would be 100 newtons however in the

105
00:13:10,179 --> 00:13:14,440
moon to calculate the weight we would multiply the mass which are the same 10

106
00:13:14,440 --> 00:13:20,379
kilograms but this time for the gravity of the moon which are 1.6 1.6 the

107
00:13:20,379 --> 00:13:26,360
result 16 newtons as you can see the mass is the same both on earth and

108
00:13:26,360 --> 00:13:31,779
on the moon but the weight is much greater on earth than on the moon because

109
00:13:31,779 --> 00:13:39,299
because the gravity on earth is much stronger than on the moon well this is

110
00:13:39,299 --> 00:13:46,639
toda la teoría que tenéis que hacer por hoy. Ahora tendríais que... You should go back here,

111
00:13:47,960 --> 00:13:58,580
get into the plus zone, and go to the digital activities, and do activity 5, gravity and weight,

112
00:13:58,580 --> 00:14:04,820
click on the sentences related to gravity. Which of these one is related to gravity? You click on

113
00:14:04,820 --> 00:14:10,399
demo okay there are more than one what are which of these words of these

114
00:14:10,399 --> 00:14:14,480
phrases are related to gravity because those that are related

115
00:14:14,480 --> 00:14:22,080
you click ok there are more than one in number six click on the right answer ok

116
00:14:22,080 --> 00:14:27,019
we have to click we read the phrase and we have to see if it refers to

117
00:14:27,019 --> 00:14:32,259
gravity or weight to magnetism or weight we are reading phrase by phrase and

118
00:14:32,259 --> 00:14:39,340
we decide that it is describing and well this would be all for today but I remind you that there is

119
00:14:39,340 --> 00:14:46,940
one more livework sheet that you have to do that was also on the table for today

120
00:14:46,940 --> 00:14:54,500
agree and that next day of this week you also have another sheet to do in

121
00:14:54,500 --> 00:15:00,440
livework sheets that is, this means that you have to do two sheets of livework sheets this

122
00:15:00,440 --> 00:15:07,519
week good guys a hug to all and that you are very good