Answer:
The tension on the string is
Explanation:
From the question we are told that
The mass of the rock is 
The density of the rock is
Generally the volume of the rock is mathematically evaluated as

substituting values


The volume of the rock immersed in water is
substituting values


mass of water been displaced by the this volume is
According to Archimedes principle
=> 

The weight of the water displace is



The actual weight of the rock is

The tension on the string is
substituting values
Answer:
x = 4,138 m
Explanation:
For this exercise, let's use the rotational equilibrium equation.
Let's fix our frame of reference on the left side of the pivot, the positive direction for anti-clockwise rotation
∑ τ = 0
n₁ 0 - W L / 2 + n₂ 4 - W_woman x = 0
x = (- W L / 2 + 4n2) / W_woman
Let's reduce the magnitudes to the SI System
M = 6 lbs (1 kg / 2.2 lb) = 2.72 kg
M_woman = 130 lbs = 59.09 kg
Let's write the transnational equilibrium equation
n₁ + n₂ - W - W_woman = 0
n₁ + n₂ = W + W_woman
n₁ + n₂ = (2.72 + 59.09) 9.8
At the point where the system begins to rotate, pivot 1 has no force on it, so its relation must be zero (n₁ = 0)
n₂ = 605,738 N
Let's calculate
x = (-2.72 9.8 6/2 + 4 605.738) / 59.09 9.8
x = 4,138 m
Answer:

Explanation:
The speed is by definition the distance traveled divided over the time it takes to travel that distance. In this case, this distance is the circumference of the wheel, so we have:

where we have written the circumference in terms of its radius.
For our values we then obtain the value:

Answer:
That is, mechanical waves cannot travel through a vacuum. This feature of mechanical waves is often demonstrated in a Physics class. A ringing bell is placed in a jar and air inside the jar is evacuated. Once air is removed from the jar, the sound of the ringing bell can no longer be heard.