B.absorb neutrons to prevent chain reactions which become uncontrollable
Kepler's three laws of planetary motion can be stated as follows: (1) All planets move about the Sun in elliptical orbits, having the Sun as one of the foci. (2) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.
Answer:
acceleration = 45 m/s²
Time = 20 seconds
Explanation:
We are given;
Distance; s = 90m
Final velocity;v = 90 m/s
Since shot from rest, initial velocity;u = 0 m/s
So, to find the acceleration, we can use Newton's 2nd law of motion which is;
v² = u² + 2as
Where a is acceleration
Plugging in the values;
90² = 0² + 2a(90)
8100 = 180a
a = 8100/180
a = 45 m/s²
Now, for the time, we will use Newton's 1st law of motion which is;
v = u + at
Where t is time;
So;
90 = 0 + 4.5t
90 = 4.5t
t = 90/4.5
t = 20 seconds
Answer:
In a standing sound wave in a pipe, nodes are regions of mean atmosphere pressure and low displacement.
