Oscillation is a type of periodic motion which repeats itself to and from about a point which is called mean position. The period of a Pendulum can be described as a ratio between the length and gravity as,

Here,
L = length
g = Gravity
If we rearrange to find the length we have that,

Our period is 2s and the gravity is 9.8m/s^2, then,


The simple required length of the pendulum must be 0.9929m
Masa is a concept that identifies that magnitude of a physical nature that allows indicating the amount of matter in a body. Within the International System , its unit is the kilogram ( kg . )
Answer:

Explanation:
As we know that charge is always conserved
so here we have
initial total charge = final total charge
also we know that gamma rays are chargeless and massless particles
so we have
charge on deuterium is given as
Q = charge on proton + charge on neutron - charge on gamma
so we have

