Answer:
because well I dont even know sorryy but you got this
C. Observations and measurements
The time taken to complete her run is 1.9 hr.
<u>Explanation:</u>
Speed is a scalar quantity and it is defined as the ratio of distance covered to the time taken to cover that distance. As distance is also a scalar quantity, so the directions given in the problem can be ignored. Thus, the distance covered by the jogger is the sum of kilometers given in problem.
Distance covered = 6+5+4 = 15 km
And the speed is given as 8 km/hr.
So the time taken will be ratio of distance to speed.

So the jogger will take 1.9 hr to complete her run.
Answer:
Explanation:
We shall apply here Doppler's effect in optics . The formula is as follows

Δλ is change in wavelength , λ is original wavelength , v is velocity and c is velocity of light
Δλ = 685 - 590 = 95 nm
λ = 685
95 / 685 = v / 3 x 10⁸
v = .416 x 10⁸ m / s
= 4.16 x 10⁷ m /s
Answer: The decibel scale is a logarithmic scale where each bel or 10 decibels correspondents to a factor of ten. A power intensity of 10^(-12) watts per square meter is the standard reference for a SPL of 0 db. So an SPL of 98 db corresponds to a power intensity of 10^(9.8)*10^(-12) or 10^(9.8–12) w/m^2.
0.006309573 w/m^2.
You can also readily find the value for any given SPL using the online calculator at: http://www.sengpielaudio.com/calculator-soundlevel.htm
Explanation: