Justin notices a particular type of caterpillar feeds only on cottonwood trees in his neighborhood.In which way has Justin increased his scientific knowledge, Justin increased his powers of scientific observation. His observation is empirical evidence. Empirical relies on observation and experimentation.
It will help you..........
<span>9.50x10^2 newtons
A pascal is defined as 1 newton per square meter. So let's multiply the pressure by the surface area of the box lid.
F = 1.00x10^-2 m^2 * 9.50x10^4 N/m^2 = 9.50x10^2 N
So it will take 9.50x10^2 newtons of force to remove the lid from the box.</span>
The frequency of the wave is 
Explanation:
The frequency, the wavelength and the speed of a wave are related by the following equation:

where
c is the speed of the wave
f is the frequency
is the wavelength
For the radio wave in this problem,


Therefore, the frequency is:

Learn more about waves here:
brainly.com/question/5354733
brainly.com/question/9077368
#LearnwithBrainly
Answer: V = 15 m/s
Explanation:
As stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. The observed frequency the car will be experiencing will be addition of the two frequency. That is,
F = 2.1 × 10^10 + 1030 = 2.100000103×10^10Hz
Using doppler effect formula
F = C/ ( C - V) × f
Where
F = observed frequency
f = source frequency
C = speed of light = 3×10^8
V = speed of the car
Substitute all the parameters into the formula
2.100000103×10^10 = 3×10^8/(3×10^8 -V) × 2.1×10^10
2.100000103×10^10/2.1×10^10 = 3×108/(3×10^8 - V)
1.000000049 = 3×10^8/(3×10^8 - V)
Cross multiply
300000014.7 - 1.000000049V = 3×10^8
Collect the like terms
1.000000049V = 14.71429
Make V the subject of formula
V = 14.71429/1.000000049
V = 14.7 m/s
The speed of the car is 15 m/s approximately
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. this means that electromagnetic waves can travel not only trough air and solid materials, but also trough the vacuum of space.