Any Scientists out there?? Serious answers please!?

Question

H/W question: Describe in terms of mass and weight the journey of a can of beans with a mass of 0.5kg from a shop in the north pole to a launch pad on the equator all the way to the moon.

This is my nephews science homework for tonight, I'm completely baffled!!! Can anyone help us out please??????! Thank You!

THANK YOU! THANK YOU! THANK YOU!

Hi I'm the nephew! The help was FANTASTIC! Thank you so much - I reckon my teacher will be really impressed! Thanks! =D

Answer 1

Okay, this seems like a baffling question, but I think what you're asking is what happens to the mass and weight of a can of beans, as it's moved from the North Pole to the Equator, and thence on a straight line to the moon. Okay, fortunately for you, half of the problem is already solved: The mass 0.5 kg is exactly the same during the entire journey. It's exactly the same no matter where it goes, until it meets with antimatter, after which it's gone. But the weight story is trickier, since weight is the product of mass and gravitational force, and it goes like this:

1. At the North Pole, 0.5 kg
2. At the Equator, VERY slightly less than 0.5, owing to the fact that the centrifugal force of the rotation of the earth is counteracting its gravitation. But this is so small, ordinary scales won't be able to detect the difference.
3. As it leaves Earth for the moon, the weight will drop steadily, until it reaches a certain point between Earth and Moon, called "Lagrange Point 1", where the gravitational pull by Earth and Moon balances out, and it weighs nothing. Thereafter, as it continues to the Moon, the weight increases.
4. At the Moon, the weight of the can of beans is roughly 1/6th of what it was originally on Earth, because the moon's lesser mass has less gravitational pull than Earth's.

Hope your nephew can impress his teacher.

Answer 2

This would be my guess of what they are asking. The question wants you to compare the mass and weight of the can of beans at all points during its journey. Remember that mass is an intrinsic property of matter. Matter has mass, which is like the measurement of the amount of stuff you have. Weight is a special kind of force related to gravitational field strength.

At all points in the journey, mass stays the same as nothing is added or taken away from the can of beans. Weight is not constant as you are changing the gravitational field strength in the part of the journey from Earth to the moon.

North Pole to equator: mass is constant and weight is constant as you will stay about the same distance from the center of mass of the Earth

From the Earth to moon: mass is constant, weight will decrease as you leave Earth, getting farther from the center of mass of the Earth until you get to a point between the Earth and the moon (not right in the exact middle but somewhere in between). After this point weight will increase as you approach the moon as a result of the moon's gravitational field.

I hope this helps you out a little.

Answer 3

The mass remains constant, so it will always be 0.5 kg.

The "weight" will change, depending on the gravitational field and external acceleration applied to the can.
The can will, for example, weigh less at the equator than at the North Pole for two reasons:
a) our planet is flattened at the poles, and thus at the North Pole the can would be closer to the center of mass of the Earth.
b) our planet is spinning on its axis, and that provides a greater acceleration away from the Earth at the equator than at the poles.

Once at the equator, you load it onto a rocket. The rocket starts by accelerating upward. Objects within the rocket will act as if a downward force is being applied to them, and so, the can will weigh more.
When the rocket stops accelerating, the can will weigh less... and the farther away from the center of mass of the Earth it is, the less it weighs.
Eventually, the rocket will be approaching the moon, and the can will be attracted more by the moon's gravity -- but there's a balance point between the Earth and Moon at which the can will experience "weightlessness."
The rocket will turn tail toward the moon, and begin decelerating -- which is an accleration, and again, will make the can seem heavier. The can will get to the moon. At the moon's surface, the gravity is about one-sixth Earth's, so the can will weigh about one-sixth what it does at rest on Earth.

Answer 4

I see that sadism is alive and well in our schools!

The mass of the can of beans will remain unchanged throughout this fantastic journey. The weight, however, will gradually decrease very slightly as it goes to the equator due to the increase in radius of the Earth and the increase in "centrifugal" force. The thrust then required to lift it off the Earth on the way to the Moon would (generally) result in it's weighing 4 to 10 times as much as it did at the equator. Once the thrust is cut off, the weight obeys the inverse square law combining the "weights" from both Earth and Moon. If it passes the "interphase" between the Earth and Moon's gravitational fields on a line between the centers of both, it will have 0 weight with respect to both bodies. The weight wil then gradually increase until it reaches its full Moon weight, about 1/6 of its Earth weight. This, of course, ignores the braking thrust required to land it on the Moon instead of smearing it all over.

As if that were not enough, the can also has a component of weight due to the Sun, which will remain relatively constant throughout. Just contemplating the addition of all these weights has driven me to the Tylenol bottle

Answer 5

I posted the whole poem if you want to see it. Thanks for commenting on it :)