We will either die cause with no gravity then we cant breathe or we may die due to the fact were in space or maybe be frozen due to the fact we will be 500k feet up air
Answer:
See the answers below
Explanation:
This problem can be solved by means of the law of conservation of energy, which tells us that the energy between two points is conserved, that is, remains the same.
That is to say, we have two points, the point A where it starts to move and reaches the point B that is 1.5 [m] high, where it stops.
The key to solving this problem is to identify the types of energies at each point. At point A we have kinetic energy and potential energy where the block moves at speed 3 [m/s] at a height of 4 [m]. Whereas at Point B we only have potential energy, since the body is at a height of 1.5 [m], relative to the ground.
a)
Since between the displacement between points A and B there is a friction force, this friction force decreases the final energy in B, in this way the energy or work of the friction will have a negative sign.
Now replacing in the above equation.
b)
We must use the same equation, but this time eliminating the Working term due to friction.
As we can see without friction the block can reach a higher height
Answer:
r₂ = 1,586 m
Explanation:
For this problem we are going to solve it by parts, let's start by finding the sound intensity when we are 25 m
β = 10 log (I / I₀)
where Io is the sensitivity threshold 10⁻¹² W / m²
I₁ / I₀ =
I₁ = I₀ e^{\beta/10}
let's calculate
I₁ = 10⁻¹² e^{25/10}
I₁ = 1.20 10⁻¹¹ W / m²
the other intensity in exercise is
I₂ = 10⁻¹² e^{80/10}
I₂ = 2.98 10⁻⁹ W / m²
now we use the definition of sound intensity
I = P / A
where P is the emitted power that is a constant and A the area of the sphere where the sound is distributed
P = I A
the area a sphere is
A = 4π r²
we can write this equation for two points of the found intensities
I₁ A₁ = I₂ A₂
where index 1 corresponds to 25m and index 2 to the other distance
I₁ 4π r₁² = I₂ 4π r₂²
I₁ r₁² = I₂ r₂²
r₂ = √ (I₁ / I₂) r₁
let's calculate
r₂ = √ (1.20 10⁻¹¹ / 2.98 10⁻⁹) 25
r₂ = √ (0.40268 10⁻²) 25
r₂ = 1,586 m
Please find attached photograph for your answer. Hope it helps. Please do comment
The distance is measured between the 'centers of mass',
or 'centers of gravity' of both objects. That's the point inside
the object where there's the same amount of mass in every
direction away from it.
If the object is something like a sphere, or a cube, or a uniform
wooden board, or anything "symmetrical", then the center of mass /
center of gravity is the actual center of the object. If the object has
some irregular shape, then it's harder to calculate or measure where
its center is.