Answer:
a) 0.0288 grams
b) 
Explanation:
Given that:
A typical human body contains about 3.0 grams of Potassium per kilogram of body mass
The abundance for the three isotopes are:
Potassium-39, Potassium-40, and Potassium-41 with abundances are 93.26%, 0.012% and 6.728% respectively.
a)
Thus; a person with a mass of 80 kg will posses = 80 × 3 = 240 grams of potassium.
However, the amount of potassium that is present in such person is :
0.012% × 240 grams
= 0.012/100 × 240 grams
= 0.0288 grams
b)
the effective dose (in Sieverts) per year due to Potassium-40 in an 80- kg body is calculate as follows:
First the Dose in (Gy) = 
= 
= 
Effective dose (Sv) = RBE × Dose in Gy
Effective dose (Sv) = 
Effective dose (Sv) = 
Answer:
Part a)

Part b)


Part c)


Explanation:
Part a)
frequency of light will not change with change in medium but it will depend on the source only
so here frequency of light will remain same in both water and glass and it will be same as that in air



Part b)
As we know that the refractive index of water is given as

so the wavelength in the water medium is given as



Similarly the refractive index of glass is given as

so the wavelength in the glass medium is given as



Part c)
Speed of the wave in water is given as



Speed of the wave in glass is given as



Answer:
The ball has an acceleration of -380 m/s², this means the ball slows down
An acceleration of -380 m/s² is the equivalent of 38.736 g's
Explanation:
Step 1: Data given
Velocity of the baseball at time t=0 = 38 m/s
At time t, the ball stops. This means v = 0
time before stops = 0.1s
Step 2: Calculate the acceleration
v= v0+at
with v= the velocity of the ball at time t = 0. v= 0
with v0 = the velocity of the ball at time t=0. v0 = 38 m/s
with a= the acceleration in m/s²
with t = time in seconds
0 = 38 + a*0.1
a = -380 m/s²
The ball has an acceleration of -380 m/s², this means the ball slows down
An acceleration of -380 m/s² is the equivalent of 38.736 g's