Well there is many ways we are not evolved as much as we think we are from being we die from a lot of diseases to world hunger and other things to be honest humans are far from being really evolved in life we really need to focus on cures and solving world hunger and fighting among ourselves
Hope this helps
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:
75degree don't forget wind and gravity force pulling down
All of the above.
if your car is on a steep hill it needs force to stop moving and to speed up
Answer:
Photons.
Explanation:
Einstein explained the photoelectric effect by proposing that light is transmitted, not in the form of continuous waves, but in the form of many tiny, discrete packets of energy called photons. Photons are massless and chargeless particle. The energy of a photon is given by :
f is the frequency of photon.
