Observations and Data are FACTS. Scientists use observations and data to draw a conclusion. Observations lead to the recording of data. Scientists ask questions about their observations and then collect data to answer their questions, then they have their evidence. Opinions are not facts, they are simply beliefs or value judgements. Then the scientist should repeat the experiment the results from different scientists should be similar- if the results are not similar and consistent then the experiment must be done again.
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Answer:
Explanation:
frequency of whistle = 1.85 x 10² = 185 Hz
frequency of beat heard = 8 beat /s . No of beat produced is equal to difference of frequencies of two sound source . Here difference is created due to Doppler effect . One of the train is moving so it will have apparent frequency which is different one from its original frequency .
When the moving train is approaching the observer , its frequency will be higher . As beat is heard at the rate of 8 beats / s , apparent frequency of approaching train will be 185 + 8 = 193 Hz .
Applying Doppler's formula of apparent frequency ,
193 = 185 x V / ( V - v ) , where V is velocity of sound and v is velocity of train .
193 V - 193 v = 185 V
193 v = 8 V
v = 8 x V / 193
= 8 x 343 / 193
= 14.21 m /s
Second possibility is that apparent velocity is less ie 185 - 8 = 177 Hz
In that case moving train will be moving away from observer . If its velocity be v
177 = 185 x V / ( V + v )
177 V + 177 v = 185 V
v = 8 x 343 / 177
= 15.50 m /s .
Answer:
Sound waves travels fastest in solids.
Sound waves travels slowest in gases.
Explanation:
Sound waves travels fastest in solids.
Sound waves travels slowest in gases.
A step-down transformer has more loops in : A. Primary coil
Primary coil refers to the coil to which alternating voltage is supplied. It's usually connected to the AC supply
hope this helps
