Answer:
Explanation:
Initial angular velocity ω₁ = 0 , final angular velocity ω₂ = 75.9 rad /s
angle rotated = θ
= 37 x 2π
= 74 π
The formula for angular velocity
ω₂² = ω₁² + 2αθ , α is angular acceleration
75.9² = 0 + 2 α x 74 π
α = 75.9² / 2 x 74 π
= 12.396 rad / s²
Answer:
Explanation:
Let T be the tension
For linear motion of hoop downwards
mg -T = ma , m is mass of the hoop . a is linear acceleration of CG of hoop .
For rotational motion of hoop
Torque by tension
T x R , R is radius of hoop.
Angular acceleration be α,
Linear acceleration a = α R
So TR = I α
= I a / R
a = TR² / I
Putting this value in earlier relation
mg -T = m TR² / I
mg = T ( 1 + m R² / I )
T = mg / ( 1 + m R² / I )
mg / ( 1 + R² / k² )
Tension is less than mg or weight because denominator of the expression is more than 1.
Answer:
= ( ρ_fluid g A) y
Explanation:
This exercise can be solved in two parts, the first finding the equilibrium force and the second finding the oscillating force
for the first part, let's write Newton's equilibrium equation
B₀ - W = 0
B₀ = W
ρ_fluid g V_fluid = W
the volume of the fluid is the area of the cube times the height it is submerged
V_fluid = A y
For the second part, the body introduces a quantity and below this equilibrium point, the equation is
B - W = m a
ρ_fluid g A (y₀ + y) - W = m a
ρ_fluid g A y + (ρ_fluid g A y₀ -W) = m a
ρ_fluid g A y + (B₀-W) = ma
the part in parentheses is zero since it is the force when it is in equilibrium
ρ_fluid g A y = m a
this equation the net force is
= ( ρ_fluid g A) y
we can see that this force varies linearly the distance and measured from the equilibrium position
Answer: A) 
Explanation:
The equation for the moment of inertia
of a sphere is:
(1)
Where:
is the moment of inertia of the planet (assumed with the shape of a sphere)
is the mass of the planet
is the radius of the planet
Isolating
from (1):
(2)
Solving:
(3)
Finally:
Therefore, the correct option is A.