Where are the images?!?!?
Answer:
Explanation:
Using the first law of thermodynamics:
Where 
is the change in the internal energy of the system, in this case 
, 
is the heat tranferred, and 
is the work, 
with a negative sign since the work is done by the system.
From the previous equation we solve for heat, because it is the unknown variable in this problem
And replacing the known values:
The negative sign shows us that the heat is tranferred from the system into the surroundings.
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:4kg
Explanation:
acceleration due to gravity(g)=10m/s^2
Weight(w)=40N
Weight=mass x g
40=mass x 10
Divide both sides by 10
Mass =40/10
Mass=4kg
