If a man stood in a large container which was on a scale and the scale showed that the total weight of the container and the man was 250 pounds (the man weighs 175 pounds) .....what weight would register on the scale while the man jumped up in the air? (during the time he was up in the air). Please explain your answer.
2007-10-14 14:39:45 · 6 answers · asked by me 1 in Science & Mathematics ➔ Physics
The scale would register 75lbs. The scale would regeister the man's mass no more than it would register the mass of a bird flying overhead. What we call 'weight' is a force. It's the force that the ground (relative) pushes up on you. So your weight 'W' equals your mass 'm' multiplied by gravity 'g'. W=m*g. That's why you'd weigh more on Jupiter, it has more gravity, and less on the moon, it has less gravity. And that's why you're weightless in free space, there is no gravity. All the while, your mass stays the same. So your weight in the metric system is expressed in units of force, Newtons (N), but your mass is in kilograms. In the US we mistakenly use pounds for both, but pounds are a unit of force, and are weight. Mass is actually measured in something called slugs in the US system.
2007-10-14 15:02:48 · answer #1 · answered by varcityplayer50 3 · 0⤊ 0⤋
Matt and others are correct. It's like this: a 747 still weighs tons when it is flying, but the wings provide the lift to hold it airborne above the "scale" of the earth's surface. When your jumper lands, he will again register 250 pounds inside his container, but his weight has never changed, since he was always at the same distance from the center of the earth (within a few inches anyway). The force that he applies during his jump temporarily overcomes the effects of gravity, but does not change his mass, and weight is the simply mass x the gravitational acceleration acting on that mass.
2007-10-14 22:01:07 · answer #2 · answered by Larry454 7 · 0⤊ 0⤋
The scale would register 75 pounds. Why?
You need to analyze the forces acting on the scale. After the man pushes off the scale and is in the air he is no longer contributing to the forces acting on the scale (technically his gravity, the gravity produced by his mass, is acting on the scale but that force is so minimal it can be ignored). However, he still has a weight, since gravity is still acting on him. Its simply not being measured while he is in the air. This assumes the man is not connected to the container in any way.
2007-10-14 21:54:32 · answer #3 · answered by kinger7102 2 · 0⤊ 0⤋
While the man jumped up in the air, scale register only weight of container.
2007-10-14 21:53:23 · answer #4 · answered by ecosierra51 2 · 0⤊ 0⤋
The man doesn't weigh less when he's in the air, he's just not on the scale. You get the same effect if he stands next to the scale, he doesn't have to be up in the air.
Do you imagine you weigh less when you are flying in an airplane?
This is exactly like the question about the tree falling? If no one was around to hear the sound did it really make a sound? Yes.
2007-10-14 22:15:42 · answer #5 · answered by Durian 6 · 0⤊ 0⤋
the scale only measures the weight when the man is standing on it, so if he is in the air only the container will register.
the scale would read 75 lbs
2007-10-14 21:50:35 · answer #6 · answered by Mαtt 6 · 1⤊ 0⤋