Explanation:
I think for anyone to answer this we need more info on what you want answered. The Sentence Itself doesn't Make Since To Me
Rate of change of speed is the acceleration of something. If something is accelerating then a force is acting on it. In everyday life we need to calculate forces and make sure they are the right value.
Answer:
d = ( -0.3 , 0.7 ) miles
Explanation:
The complete question is as follows:
" Take the north direction as the positive y direction and east as positive x. The origin is still where the student starts biking. Let d⃗ N be the displacement vector corresponding to the first leg of the student's trip. Express d⃗ N in component form.
Express your answer as two numbers separated by a comma (e.g., 1.0,2.0). By convention, the x component is written first.
A student bikes to school by traveling first dN = 0.800 miles north, then dW = 0.300 miles west, and finally dS = 0.100 miles south. "
Solution:
- The displacement vector d N is vector sum of all journeys. We will express +x as +i and +y as +j. Then displacement vector is given by:
d = dN + dW + dS
d = 0.8 j - 0.3 i - 0.1 j
d = - 0.3 i + 0.7 j
- The displacement vector d in component form is d = ( -0.3 , 0.7 ) miles
Answer:
A) I = 0.09947 W
, β = 109 db
, B) β = 116 db
, β = 116 db
, c) Δβ = 7 dB,
D) P = 50.27 W
Explanation:
A) The intensity of a spherical sound wave is
I = P / A
where A is the area of the sphere where the sound is distributed
A = 4π R²
we substitute
I = P / 4πR²
let's calculate
I = 500 / (4π 20²)
I = 0.09947 W
to express this quantity in decibels we use relate
β = 10 log (I / I₀)
The detectivity threshold is I₀ = 1 10⁻¹² W / m²
β = 10 lob (0.09947 / 10⁻¹²)
β = 10 (10.9976)
β = 109 db
B) intensity at r = 10m
I = 500 / (4π 10²)
I = 0.3979 W / m²
β = 10 log (0.3979 / 10⁻¹²)
β = 10 (11.5997)
β = 116 db
C) the change in intensity in decibles is
Δβ = β₁ - β₂
Δβ = 116 - 109
Δβ = 7 dB
D) let's find the intensity for 100 db
I = I₀ 10 (β / 10)
I = 10⁻¹² 10 (100/10)
I = 10⁻² W / m²
Thus
P = I A
P = I 4π R²
P = 10⁻² 4π 20²
P = 50.27 W
