Answer: 1.39 s
Explanation:
We can solve this problem with the following equations:
(1)
(2)
Where:
is the length the steel wire streches (taking into account 1mm=0.001 m)
is the length of the steel wire before being streched
is the force due gravity (the weight) acting on the pendulum with mass 
is the transversal area of the wire
is the Young modulus for steel
is the period of the pendulum
is the acceleration due gravity
Knowing this, let's begin by finding
:
(3)
Where
is the diameter of the wire
(4)
(5)
Knowing this area we can isolate
from (1):
(6)
And substitute
in (2):
(7)
(8)
Finally:

Explanation:
Equilibrium position in y direction:
W = Fb (Weight of the block is equal to buoyant force)
m*g = V*p*g
V under water = A*h
hence,
m = A*h*p
Using Newton 2nd Law

Hence, T time period
T = 2*pi*sqrt ( h / g )
Answer:
méthode if séparation muddy water
Answer:
The answer to your question is m₂ = 38.5 kg
Explanation:
Data
distance = d = 2.1 x 10⁻¹ m
Force = 3.2 x 10⁻⁶ N
m₁ = 55 kg
m₂ = ?
G = 6.67 x 10 ⁻¹¹ Nm²/kg²
Process
1.- To solve this problem use Newton's law of Universal Gravitation.
F = G m₁m₂ / r²
-Solve for m₂
m₂ = Fr² / Gm₁
2.- Substitution
m₂ = (3.2 x 10⁻⁶)(2.1 x 10⁻¹)² / (6.67 x 10⁻¹¹)(55)
3.- Simplification
m₂ = 1.411 x 10⁻⁷ / 3.669 x 10⁻⁹
4.- Result
m₂ = 38.5 kg
Answer:
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