A. 0.5kg
To get this answer you need to follow the equation of KE=0.5*mv^2
But we don't have the m part in the equation. So just plug in the numbers to see which works best, though I can tell you before we do that the answer would be a.
As you may know, gravity, is a force of 9.8 m/s. And we want to get 9.8 Joules. So if we take a half a kg stone, release it at one meter, we get half of the normal gravity pull, 4.90 Joules. That means if we take half a kg stone and drop it at a doubled height, we get 9.8 Joules.
That is also to say that if we have a 1kg stone and drop it at one meter you will get the normal pull of gravity in Joules, 9.8J.
Be careful though, this does not mean if you drop a 1kg stone and a .5 kg stone the 1kg will hit first. This simply means that the 1kg stone will have twice the Joules that the .5kg stone has.
Answer:

Explanation:
<u>Given:</u>
- Mass,
- Velocity,

where,
are the uncertainties in mass and velocity respectively.
The kinetic energy is given by

The uncertainty in kinetic energy is given as:

Answer:
yes bc it washed it away so
Explanation:
(:
Hi there! When a chemical Reaction happens, the tell tale signs are as listed:
~The chemical produces bubbles
~ The Chemical emits an odor
~ The liquid forms a solid(Precipitate)
~ There is a change of color
~ And last but not least a change in temperature!
Hope this can help! Good luck!