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♫ Musical introduction ♫
Do any of you know how much do you weigh?
I weigh 35 kg (77lb).
I weigh 32 kg (70lb).
I weigh 33 kg (73lb).
I weigh 36 kg (79lb).
Why do you weigh differently?
Because some of us are bigger than others, or we’ve got bigger muscles.
That's partially true, but also because we are weighing ourselves on Earth.
Would you weigh the same on the Moon as here on the Earth?
No, objects weigh less on the Moon than on the Earth.
Very good, Maiko!
That means that your weight is not only related to the mass each of you’ve got in your bodies,
but also with the gravity.
The higher the amount of mass in an object -that is, the stronger the gravity-, the more that object will weigh.
So, what’s gravity?
Is the force with which each planet attracts objects that are close to it.
Generally speaking, we can say that in the solar system, the bigger the planet, the stronger the gravity
In ancient times, when the difference between weight and mass wasn’t known
people used to say that an object was "gravis" if it was heavy, that's why the gravity’s received that name.
According to what Maiko said in class, objects weigh less on the Moon than on the Earth.
Does this mean that I don’t weigh the same on any planet?
No. The smaller a planet is, the less its gravity will be, and consequently, the less its force of attraction too.
So would I be smaller?
No, you wouldn’t be smaller and you wouldn’t weigh less because of that.
The mass of your body would be the same on the Earth than on the Moon, it is the gravity which would change.
Does it change a lot?
I don’t know. I’ve got a book here with information about other planets. Look...
I want to know in which planet I’d weigh more and in which, less
Ok. What changes the weigh between one planet and another is the gravity, but anyway
the moon is not a planet but a natural satellite.
Yes, of course. The teacher said that the bigger planets are the ones with the strongest gravity,
and the smaller, with the lowest.
Let’s start by the smallest. Which is it?
Although it’s no longer considered a planet, for many years the smallest planet and the one farthest from the Sun was Pluto.
Where would I weigh more?
On the biggest one, Jupiter! According to this book, any object would weigh two and a half times more on Jupiter than on the Earth.
Wow! So, if I weigh 30 kg here, in Jupiter I’d weigh...
75kg (165 lb)!
In Aula365 Speedy there's a lot more to learn and enjoy, don't miss it!
Aula365 Speedy, celebrating knowledge.