Nuclear fission formula by the looks of it. Possibly how Professor Lisa Meitner realised that she had split the atomic nucleus. The Xenon and the Strontium (Xe and Sr) would presumably show up in a radio chemical assaying test at her university.
A few years later, Professor J Robert Oppenheimer watched a nuclear test somewhere near Los Alamos, US and lamented "I am become death, the destroyer of worlds". Shortly thereafter, Hiroshima and Nagasaki were razed to the ground and annihilated by nuclear bombs. Professor Meitner, probably inadvertently, had got the keys to the doors to "nuclear hell", and JRO ended up turning them. Something like that maybe, and a very harrowing and tumultuous period in human history.
Note in the fission equation, that out come two neutrons. They go off and produce a similar fission in another U235 nucleus into a chain reaction which, i not moderated by, say, Boron, can end up as a "mushroom cloud".
Answer:
The magintude of the acceleration for both objects is 
Explanation:
Drawing a free body diagram on the two boxes we can analyze the system more easily.
we can take the acceleration going up as positive for reference purposes.
for mA let's suppose that is ascending so:
and for mB (descending):
because the two boxes has the same acceleration because they are attached together:
So the magintude of the acceleration for both objects is
-- She went up for 0.4 sec and down for 0.4 sec.
-- The vertical distance traveled in gravity during ' t ' seconds is
D = (1/2) x (g) x (t)²
= (1/2) (9.8 m/s²) (0.4 sec)²
= (4.9 m/s²) x (0.16 s²)
= 0.784 meter ( B )
Answer:
acceleration = v-u /t
30- 20/5
= 10/5 = 2m/sec²
Force = mass * acceleration
Force = 0.1 * 2
Force = 0.2 Newton
