The correct answer is c because B) is a vector which includes both velocity and direction
Answer:
0.0000076 grams
Explanation:
We're given the half life of Tritium to be 12.3 years. In order to find out the amount of substabce remaining:
Let's first find how many 'half lives' are in 250 years.

Now what is half life? It means the time taken for a given quantity of an element to lose half it's mass.
So in 12.3 years we can find that The amount of 250 g of Tritium will be 250/2 = 125 g. In 24.6 years we'll have 125/2 = 62.5 g
So now we can devise a formula:

Where m is the remaining amount and n is th number of half lives in the time given.
Using this formula we can calculate:

Doing this calculation we get:

As we can see a very small value remains.
Answer:
wavelength = 0.968 m
frequency = 39.02 Hz
Explanation:
given data
mass = 0.0127 kg
force = 9.33 N
length = 1.93 m
to find out
wavelength and Frequency
solution
we know here linear density that is
linear density =
.........1
linear density =
linear density = 6.5803 ×
kg/m
so
wavelength will be here
wavelength =
..............2
here n = 4 for forth harmonic
wavelength = 
wavelength = 0.968 m
and
frequency will be for 4th normal mode of vibration is
frequency =
..........3
frequency = 
frequency = 1.036269 × 37.654594
frequency = 39.02 Hz