I think its gonna be 106
154-48=106
ie;mass number - atomic number = neutron number
Iodine-131 has a half life of 8 days, so half of it is gone every 8 days.
10 grams of iodine-131 is left for 24 days.
At 8 days: 10/2=5 grams left
At 16 days: 5/2=2.5 grams left
At 24 days: 2.5/2=1.25 grams left.
**
Your mistake is that you stopped at 16 days.
D. The flow of energy,heat, and work
Answer:
it is safe to stand at the end of the table
Explanation:
For this exercise we use the rotational equilibrium condition
Στ = 0
W x₁ - w x₂ - w_table x₃ = 0
M x₁ - m x₂ - m_table x₃ = 0
where the mass of the large rock is M = 380 kg and its distance to the pivot point x₁ = 850 cm = 0.85m
the mass of the man is 62 kg and the distance
x₂ = 4.5 - 0.85
x₂ = 3.65 m
the mass of the table (m_table = 22 kg) is at its geometric center
x_{cm} = L/2 = 2.25 m
x₃ = 2.25 -0.85
x₃ = 1.4 m
let's look for the maximum mass of man
m_{maximum} =
let's calculate
m_{maximum} = (380 0.85 - 22 1.4) / 3.65
m_{maximum} = 80 kg
we can see that the maximum mass that the board supports without turning is greater than the mass of man
m_{maximum}> m
consequently it is safe to stand at the end of the table
Answer:
The speed of the vehicles immediately after the collision is 5.84 m/s.
Explanation:
The speed of the vehicles after the collision can be found by conservation of linear momentum:
Where:
m₁: is the mass of the car = 0.5 ton = 500 kg
m₂: is the mass of the lorry = 9.5 ton = 9500 kg
: is the initial speed of the car = 40 km/h = 11.11 m/s
: is the initial speed of the lorry = 20 km/h = 5.56 m/s
: is the final speed of the car =?
: is the final speed of the lorry =?
Since the two vehicles become tightly locked together after the collision = :
Therefore, the speed of the vehicles immediately after the collision is 5.84 m/s.
I hope it helps you!