Answer:
A free body diagram with 2 forces: the first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 20 N.
Explanation:
This is because at terminal velocity, the ball stops accelerating and the net force on the ball is zero. For the net force to be zero, equal and opposite forces must act on the ball, so that their resultant force is zero. That is F₁ + F₂ = 0 ⇒ F₁ = -F₂
Since F₁ = 20 N, then F₂ = -F₁ = -20 N
So, if F₁ points upwards since it is positive, then F₂ points downwards since it is negative.
So, a free body diagram with 2 forces: the first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 20 N best describes the ball falling at terminal velocity.
Answer:
The age of living tree is 11104 years.
Explanation:
Given that,
Mass of pure carbon = 100 g
Activity of this carbon is = 6.5 decays per second = 6.5 x60 decays/min =390 decays/m
We need to calculate the decay rate
....(I)
Where, N = number of radio active atoms
=half life
We need to calculate the number of radio active atoms
For 

Where,
=Avogadro number


For 



Put the value in the equation (I)


100 g carbon will decay with rate

We need to calculate the total half lives






We need to calculate the age of living tree
Using formula of age



Hence, The age of living tree is 11104 years.
Answer:
Her angular speed (in rev/s) when her arms and one leg open outward is 1.4 rev/s
Explanation:
given information:
moment inertia of arm and leg when in, I₁ = 0.9 kgm²
moment inertia of arm and leg when extended, I₂ = 2.9 kgm²
angular speed when in, ω₁ = 4.5 rev/s
so, her angular speed (in rev/s) when her arms and one leg open outward is
L₁ = L₂
I₁ω₁ = I₂ω₂
ω₂ = I₁ω₁/I₂
= 0.9 x 4.5/2,9
= 1.4 rev/s
Answer:
Magnetic field strength required for this is 0.25 T
Explanation:
As we know that the proton moves in circular path in uniform magnetic field
so the radius of the path of the circle is given as

here we know that




now we have

so we have
