Answer;
C.It is the minimum amount of material needed to sustain a fission reaction.
Explanation;
-A critical mass is the smallest or the minimum amount of fissile material needed for a sustained nuclear chain reaction. A critical mass must be achieved in order for the chain reaction to continue and release the atomic energy. A critical mass is needed for both a nuclear reactor and an atomic or hydrogen bomb.
-The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings.
Answer:
6844.5 m/s.
Explanation:
To get the speed of the satellite, the centripetal force on it must be enough to change its direction. This therefore means that the centripetal force must be equal to the gravitational force.
Formula for centripetal force is;
F_c = mv²/r
Formula for gravitational force is:
F_g = GmM/r²
Thus;
mv²/r = GmM/r²
m is the mass of the satellite and M is mass of the earth.
Making v the subject, we have;
v = √(GM/r)
We are given;
G = 6.67 × 10^(-11) m/kg²
M = 5.97 × 10^(24) kg
r = 8500 km = 8500000
Thus;
v = √((6.67 × 10^(-11) × (5.97 × 10^(24)) /8500000) = 6844.5 m/s.
Answer:
The Moon rotating around Earth and the Earth rotating around the Sun
Explanation:
Answer:
The maximum height of ball 2 is 4 times that of ball 1
Explanation:
We can find the maximum height of each ball by using the following suvat equation:
where
v is the final velocity
u is the initial velocity
is the acceleration of gravity (we take upward as positive direction)
s is the displacement
At the maximum height, s = h and v = 0 (the final velocity is zero), so re-arranging the equation:
The first ball is thrown with initial velocity 
, so it reaches a maximum height of
(the quantity will be positive, since g is negative)
The second ball is thrown with initial velocity
so it will reach a maximum height of
So, its maximum height will be 4 times the maximum height reached by ball 1.
Answer:
D) a Battery
Explanation:
The best real-life example of direct current is a battery. Batteries have positive and negative terminals on a battery, the electrons in the wires will begin to flow to produce a current.
