Theories result from several repeated experiments.
Theories explain observations and hypotheses.
Theories may be revised over time.
Explanation:
Scientific theories are purely explanations into an observation and hypothesis. The are general binding explanations that have been developed from several tests.
- Theories are products of different stages of experiments in their own regard.
- For a theory to be accepted by the scientific community, its hypothesis statement must be:
- Testable
- Repeated
- Falsifiable
- Based on new evidence, a theory may be revised with time. One of such is the Dalton's atomic theory with a modern atomic theory version now.
Learn more:
Experiments brainly.com/question/5096428
#learnwithBrainly
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.
There are some missing data in the text of the problem. I've found them online:
a) coefficient of friction dry steel piston - steel cilinder: 0.3
b) coefficient of friction with oil in between the surfaces: 0.03
Solution:
a) The force F applied by the person (300 N) must be at least equal to the frictional force, given by:

where

is the coefficient of friction, while N is the normal force. So we have:

since we know that F=300 N and

, we can find N, the magnitude of the normal force:

b) The problem is identical to that of the first part; however, this time the coefficienct of friction is

due to the presence of the oil. Therefore, we have:
In this question a lot of information's are provided. Among the information's provided one information and that is the time of 4 seconds is not required for calculating the answer. Only the other information's are required.
Mass of the block that is sliding = 5.00 kg
Distance for which the block slides = 10 meters/second
Then we already know that
Momentum = Mass * Distance travelled
= (5 * 10) Kg m/s
= 50 kg m/s
So the magnitude of the blocks momentum is 50 kg m/s. The correct option among all the given options is option "b".
Acceleration= change in velocity/time