Answer:
When they pull on the rope, they each slide toward each other. How do their accelerations compare and how far does each person slide before they meet? The force on each will be the same so they will always have the same acceleration -- and, because of that, the same velocity and they will move the same distance.
The answer to this is C. The reason being is because if you were to use a compass then it would be making circular motions towards the middle of the wire.
Answer:
I₂ = 0.04 W / m²
Explanation:
Sound intensity is the power emitted between the unit area
I = W / A
W = I A
sound is a wave that travels in space whereby its energy is distributed on the surface of a sphere
A = 4π r²
we substitute
W = I (4π r²)
the emission power is constant, so the intensity at two different points is
W = I₁ 4π r₁² = I₂ 4π r₂²
so the equation is
I₁ r₁² = I₂ r₂²
In this case the units are not shown in the exercise, suppose that all units are in the SI system
I₂ = 
let's calculate
I₂ = 4 
I₂ = 0.04 W / m²
Answer:
3.9 seconds
Explanation:
Use constant acceleration equation:
y = y₀ + v₀ t + ½ at²
where y is the final position,
y₀ is the initial position,
v₀ is the initial velocity,
a is the acceleration,
and t is time.
Given:
y = 0 m
y₀ = 15 m
v₀ = 15 m/s
a = -9.8 m/s²
Substituting values:
0 = 15 + 15t + ½ (-9.8) t²
0 = 15 + 15t − 4.9t²
0 = 4.9t² − 15t − 15
Solve with quadratic formula:
t = [ -b ± √(b² − 4ac) ] / 2a
t = [ 15 ± √((-15)² − 4(4.9)(-15)) ] / 2(4.9)
t = [ 15 ± √(225 + 294) ] / 9.8
t = (15 ± √519) / 9.8
t = -0.79 or 3.9
It takes 3.9 seconds for the stone to reach the bottom of the well.
The negative answer is the time it takes the stone to travel from the bottom of the well up to the top of the well.
