Answer:
The one which has a Frequency of 140Hz.
Answer: in order for a scientific investigation to be valid A hypothesis must be tested throughout a Scientific investigation that can gather evidence and support it.
Explanation: in any scientific investigation you have to have a testable hypothesis, without your hypothesis it’s not really a scientific investigation.
Hope this helped!
The launch of a rocket into space involves an excessive amount of fuel, so scientists are continuously researching new measures to make flight more efficient. This involve new types of petrol, new technologies, and structures that are more aerodynamic. Securely flying. I hope this helps. -hafsa
