X-rays are high energy electrons
that can cause damage when exposed under extreme conditions. The best technology
that can block it is using a lightweight type of metal foam. It can take in
high energy collisions which also exhibits high forces. it does not only block
x-rays but also, neutron radiation and gamma rays.
c
Immediately upon reaching its lowest point, a falling pendulum bob has its greatest amount of kinetic energy, which is less than the initial amount of potential energy.
remember the law of energy there cannot be any more since it is using the potential energy to move
N₀ = number of radioactive atoms initially present = 128
N = number of radioactive atoms left after time "t" = 2
t = time taken
T = half life period for the radioactive metal = 20 years
λ = decay constant = ?
decay constant is given as
λ = 0.693/T
inserting the values
λ = 0.693/20
λ = 0.0347
number of radioactive atoms left after time "t" is given as
N = N₀
inserting the values
2 = (128)
t = 120 years
<span>So, average angular velocity = angle/time = 90/1.5 = 60deg/second = (pi/3 radians/second) </span>
It would be 20 protons left because 1-19= 20