Question

physics help @Mathematics

Answer 1

post the question

Answer 2

wel why is weight 0 for an object in free fall?

Answer 3

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Answer 4

What's the definition of weight?

Answer 5

mg

Answer 6

There are two definitions. The first one is:

Weight is the gravitational force acting on a mass m.

If an object is in free fall, gravity is still acting on it so it still has weight.

The second one is "apparent weight":

Weight is the force acting on an object as measured by weighing it, with for example a spring scale.

With this definition, when an object is in free fall, the spring scale that's weighing it is also in free fall and the force in that frame of reference is zero, and hence the object has zero apparent weight.

To convince yourself of this, get a spring scale and try it.

I'm also going to see if I can find a good video of this for you. One minute.

Answer 7

Here: watch this. Very, very good:
http://ocw.mit.edu/courses/physics/8-01-physics-i-classical-mechanics-fall-1999/video-lectures/lecture-7/

Answer 8

oh but y force became 0 in that frame of refernce?

Answer 9

?

Answer 10

and also if we have weight while falling y do w feel weightlessness?

Answer 11

The first 6 minutes of the video has exactly the answer.

Answer 12

1A false balance has equal arms (each a ).An object weighs W1 when placed in one pan and W2 when placed in other pan.What is true weight W of the object?

Answer 13

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Answer 14

So it's a 'false' balance because the arms are of unequal length?

Answer 15

A false balance has equal arms (each a )

Answer 16

I don't understand then what is cause of its 'falseness'. Is the balanced balanced when there is no weight in either pan?

Answer 17

i tooo dont know that can u try?

Answer 18

.........

Answer 19

3 forces 50 dyne 20 dynes and 15 dynes act in a point on a body .Can body be in equilibrium?

Answer 20

Is that the entire question? I don't see it. If the balance is in balance when there are no masses in either pan, then the balance is not false. So the only way that it can show two different weights w1 and w2, is if that is not the case. And it will be not the case, if one arm is heavier than the other, by some amount, call it D for difference.

Then let W be the true weight, then on one side w1 = W + D and w2 = W - D.

Hence w1 + w2 = W - D + W + D = 2W

therefore W = (w1 + w2)/2

Answer 21

3 forces 50 dyne 20 dynes and 15 dynes act in a point on a body .Can body be in equilibrium?

No. Let the 50 dyne force be on the x axis. Then the body will be in equilibrium if the other two forces have a net x component of -50 dyne. But they can't because their combined magnitude is 35 which is less than 50.

Answer 22

where'd you go?