Answer:
v = 22.54 mph.
Explanation:
Given that,
Distance moved, d = 200 m
Time, t = 19.8 s
We need to find the runner's average speed.
We know that,
1 mile = 1609.34 m
200 m = 0.124 miles
19.8 seconds = 0.0055 h
So,
Speed = distance/time

So, the runner's average speed is 22.54 mph.
Answer:
The mass goes down
Explanation:
Because mass is the quantity of matter contained in a substance And Volume is the space occupied by a substance. So when the volume is less the mass decreases
Answer:
Long wavelength
Explanation:
Wavelengths that corresponds to the bands of blue and red are strongly absorbed whereas the wavelengths that lie in the mid-range corresponds to green light that are absorbed weakly.
Fluorescence produced is always directed towards longer wavelengths of the spectra as compared to the corresponding spectra for absorption.
Answer:
A) The wave that travels through the rail reaches the microphone first.
B) separation in time between the arrivals of the two pulses is 0.01539 seconds.
Explanation:
Detailed explanation and calculation is shown in the image below
Explanation:
First we will convert the given mass from lb to kg as follows.
157 lb = 
= 71.215 kg
Now, mass of caffeine required for a person of that mass at the LD50 is as follows.

= 12818.7 mg
Convert the % of (w/w) into % (w/v) as follows.
0.65% (w/w) = 
= 
= 
Therefore, calculate the volume which contains the amount of caffeine as follows.
12818.7 mg = 12.8187 g = 
= 1972 ml
Thus, we can conclude that 1972 ml of the drink would be required to reach an LD50 of 180 mg/kg body mass if the person weighed 157 lb.