The answer is A.
It will decay to give you Thorium and Helium.
Please give me Brainliest.
Answer:
The velocity and height is 31 m/s and 44.4 m respectively .
Explanation:
Given :
Initial speed of rock , u = 8.5 m/s .
Time taken to reach ground , t = 2.25 s .
Also , acceleration due to gravity is ,
.
Now , to find the velocity when it hit ground .
Applying equation of motion :

Also , height from which rock is thrown is given by :

Hence , this is the required solution .
Answer:
Approximately
to the right (assuming that both astronauts were originally stationary.)
Explanation:
If an object of mass
is moving at a velocity of
, the momentum
of that object would be
.
Since momentum of this system (of the astronauts) conserved:
.
Assuming that both astronauts were originally stationary. The total initial momentum of the two astronauts would be
since the velocity of both astronauts was
.
Therefore:
.
The final momentum of the first astronaut (
,
to the left) would be
to the left.
Let
denote the momentum of the astronaut in question. The total final momentum of the two astronauts, combined, would be
.
.
Hence,
. In other words, the final momentum of the astronaut in question is the opposite of that of the first astronaut. Since momentum is a vector quantity, the momentum of the two astronauts magnitude (
) but opposite in direction (to the right versus to the left.)
Rearrange the equation
to obtain an expression for velocity in terms of momentum and mass:
.
.
Hence, the velocity of the astronaut in question (
) would be
to the right.