First, we must find the vertical distance traveled upwards by the ball due to the throw. For this, we will use the formula:
2as = v² - u²
Because the final velocity v is 0 in such cases
s = -u²/2a; because both u and a are downwards, the negative sign cancels
s = 14.5² / 2*9.81
s = 10.72 meters
Next, to find the time taken to reach the ground, we need the height above the ground. This is:
45 + 10.72 = 55.72 m
We will use the formula
s = ut + 0.5at²
to find the time taken with the initial velocity u = 0.
55.72 = 0.5 * 9.81 * t²
t = 3.37 seconds
Because the object is still made of the same material
Density is not affected by the weight and shape of an object its affected by how concentrated the atoms are in a given volume
Actually it's
and it says that the energy of an object (E) is equal to the mass (m) of the object multiplied with the squared speed of light (
). This theory says that mass can be turned into energy and energy can be turned into mass. This is one of Einstein's theory of relativity.
1 year = (365 / 121) = 3.02 half-lifes. Let's call it 3 .
The amount of radioactive isotope remaining after 3 half-lifes is
(1/2) x (1/2) x (1/2) = 1/8
A year after the medical lab received the 24 kg of W-181,
there will still be 24 kg of stuff in the container.
But only 3 kg of it will still be W-181. The other 21 kg will be
whatever substances W-181 becomes when it decays.
Sadly, even the 3 kg of good stuff won't be usable anymore ...
it'll be thoroughly mixed with the 21 kg of junk. It would be harder
and more expensive to try and separate them than to buy a new
can of pure W-181, and USE it before 7/8 of it has deteriorated.
