For the part a) we need only the momentum of the box and we have the data to find it.
Momentum is given by,
where clearly, p is the momentum, m the mass of the box and v is the velocity.
Substituting,
For part b) we need an analysis of the situation. We understand that the box on a surface that has no friction will continue to rotate at the same speed previously defined. The box can only stop with friction, so,
<em>It is the same that part a)</em>
Answer:
15 less mins will be used by Bob
Explanation:
This is because it takes Tim 2000/50= 40mins to type the whole work
While it takes Bob 2000/80= 25 mins
So the difference 40-25= 15mins
Will be 15mins
Answer:
A coefficient friction is a value that shows the relationship between two objects and the normal reaction between the objects that are involved.
Explanation:
Answer:
dβ = 70. 77 dβ
Explanation:
The intensity of sound in decibels is
dβ = 10 log I/I₀
let's look for the intensity of this signal
I / I₀ = 10 dβ/10
I / I₀ = 3.981 10⁶
the threshold intensity of sound for humans is I₀ = 1 10⁻¹² W / m²
I = 3.981 10 ⁶ 1 10⁻¹²
I = 3,981 10⁻⁶ W / m²
It is indicated that 3 cornets are placed in the circle, for which total intensity is
I_total - 3 I
I_total = 3 3,981 10⁻⁶
I_total = 11,943 10⁻⁶ W / m²
let's reduce to decibels
dβ = 10 log (11,943 10⁻⁶/1 10⁻¹²)
dβ = 10 7.077
dβ = 70. 77 dβ
Apply:
wavelength = speed of wave / frequency
wavelength = 12 m/s / 4 Hz = 48 m
