Answer:
Explanation:
Let the intensity of the noise be represented by I
Given that
40dB = 10 log 10 ( I /I•) ........ 1
I• is the lowest or threshold intensity of sound made.
I represents the intensity of the sound/ noise
The intensity of noise of 1000flies will be
β = 10 log 10 (1000I/I•)
Open up the bracket
β = 10 log 10(1000)+ 10 log 10(I/I•)
10 log 10(10^3)+10 log 10(I/I•)
3×10(10 log 10) +10 log 10(I/I•)
Recall, 10 log 10 = 1
30×1 + 10 log 10(I/I•).........2
Put equation 1 into 2
β =30+40
= 70db
Answer:
C. The wheel with spokes has about twice the KE.
Explanation:
Given that
Mass , radius and the angular speed for both the wheels are same.
radius = r
Mass = m
Angular speed = ω
The angular kinetic energy KE given as

I=Moment of inertia for wheels
Wheel made of spokes
I₁ = m r²
Wheel like a disk
I₂ = 0.5 m r²
Now by comparing kinetic energy



KE₁= 2 KE₂
Therefore answer is C.
Constant speed along the inclined surface = 30 m / 4 s = 7.5 m/s
Vertical speed = inclined speed * sin(45) = 7.5 *√2 / 2 = 5.3 m/s
Answer: 5.3 m/s
Weight = (mass) x (gravity)
On Earth ...
Weight = (1 kg) x (9.8 m/s^2)
Weight = 9.8 Newtons
A) position time graph for both is shown
here one of the graph is of lesser slope which means it is moving with less speed while other have larger slope which shows larger speed
At one point they intersects which is the point where they both will meet
B) Let the two will meet after time "t"
now we can say that
if they both will meet after time "t"
then the total distance moved by you and other person will be same as the distance between you and home
so it is given as



so they will meet after t = 6 min
so from position time graph we can see that two will meet after t = 6 min where at this position two graphs will intersect