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:
The child represented by a star on the outside path.
Explanation:
Answer:
(A) It will take 22 sec to come in rest
(b) Work done for coming in rest will be 0.2131 J
Explanation:
We have given the player turntable initially rotating at speed of 
Now speed is reduced by 75 %
So final speed 
Time t = 5.5 sec
From first equation of motion we know that '

(a) Now final velocity 
So time t to come in rest 
(b) The work done in coming rest is given by

Answer:
The increase in the internal energy of the system is 360 Joules.
Explanation:
Given that,
Heat supplied to a system, Q = 292 J
Work done on the system by its surroundings, W = 68 J
We need to find the increase in the internal energy of the system. It can be given by first law of thermodynamics. It is given by :

So, the increase in the internal energy of the system is 360 Joules. Hence, this is the required solution.
Supposing that the spring is un stretched when θ = 0, and has a toughness of k = 60 N/m.It seems that the spring has a roller support on the left end. This would make the spring force direction always to the left
Sum moments about the pivot to zero.
10.0(9.81)[(2sinθ)/2] + 50 - 60(2sinθ)[2cosθ] = 0 98.1sinθ + 50 - (120)2sinθcosθ = 0 98.1sinθ + 50 - (120)sin(2θ) = 0
by iterative answer we discover that
θ ≈ 0.465 radians
θ ≈ 26.6º