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
The answer is b, anything that has mass and takes up space
Answer:
spring deflection is x = (v2 / R + g) m / 4
Explanation:
We will solve this problem with Newton's second law. Let's analyze the situation the car goes down a road and finds a dip (hollow) that we will assume that it has a circular shape in the lower part has the car weight, elastic force and a centripetal acceleration
Let's write the equations on the Y axis of this description
Fe - W = m 
Where Fe is elastic force, W the weight and
the centripetal acceleration. The elastic force equation is
Fe = - k x
4 (k x) - mg = m v² / R
The four is because there are four springs, R is theradio of dip
We can calculate the deflection (x) of the springs
x = (m v2 / R + mg) / 4
x = (v2 / R + g) m / 4
Answer:
a) I = 3.63 W / m²
, b) I = 0.750 W / m²
Explanation:
The intensity of a sound wave is given by the relation
I = P / A = ½ ρ v (2π f
)²
I = (½ ρ v 4π² s_{max}²) f²
a) with the initial condition let's call the intensity Io
cte = (½ ρ v 4π² s_{max}²)
I₀ = cte s² f₀²
I₀ = cte 10 6
If frequency is increase f = 2.20 10³ Hz
I = constant (2.20 10³) 2
I = cte 4.84 10⁶
let's find the relationship of the two quantities
I / Io = 4.84
I = 4.84 Io
I = 4.84 0.750
I = 3.63 W / m²
b) in this case the frequency is reduced to f = 0.250 10³ Hz and the displacement s = 4 s or
I = cte (f s)²
I = constant (0.250 10³ 4)²
I = cte 1 10⁶
the relationship
I / Io = 1
I = Io
I = 0.750 W / m²
Answer:
28,400 N
Explanation:
Let's start by calculating the pressure that acts on the upper surface of the hatch. It is given by the sum of the atmospheric pressure and the pressure due to the columb of water, which is given by Stevin's law:

On the lower part of the hatch, there is a pressure equal to

So, the net pressure acting on the hatch is

which acts from above.
The area of the hatch is given by:

So, the force needed to open the hatch from the inside is equal to the pressure multiplied by the area of the hatch:
