Answer:
height = 45 m
Explanation:
Initial velocity = 0 m/s
Final velocity = 30 m/s
Acceleration due to gravity = +10m/s^2 ( because ball is going down )
Using the eqn of motion
where v= final velocity ; u = initial velocity ; g = acceleration due to gravity ; h = height
So,
Here's the part you need to know:
(Weight of anything) =
(the thing's mass)
times
(acceleration of gravity in the place where the thing is) .
Weight = (mass ) x (gravity) .
That's always true everywhere.
You should memorize it.
For the astronaut on Saturn . . .
Weight = (mass ) x (gravity) .
Weight = (68 kg) x (10.44 m/s²)
= 709.92 newtons .
__________________________________
On Earth, gravity is only 9.8 m/s².
So as long as the astronaut is on Earth, his weight is only
(68 kg) x (9.8 m/s²)
= 666.4 newtons .
Notice that his mass is his mass ... it doesn't change
no matter where he goes.
But his weight changes in different places, because
it depends on the gravity in each place.
Most everyday objects have as many plus charges as they have minus charges
Answer:
Mass and thus force depends on the reference frame chosen
Explanation:
This can be explained as Newton's law of gravity provides action which are instantaneous at a distance and involves the evaluation of all the quantities at present time or at the instant they occur.
If the body undergoes a change in its mass distribution there will be an immediate change in its gravitational force without any lag.
Now, if we talk about special relativity, it would be absurd to say that an information can travel faster than light. The effect is in synchronization with the cause in one reference frame where the effect occurs after the cause for some observer in some other reference frame.
In order to observe Newton's law of gravity all the observer's in different reference frames must observe the same phenomena which could only be possible if time were absolute and in special relativity, time is not absolute.
Therefore, Newton's law of gravity was inconsistent with the Einstein's Special Relativity.
