The difference between the frequencies of the piano key and the tuning fork gives the frequency of the beats.
When the tuning fork is 405 Hz, and no beats are heard, then the piano key is also 405 Hz.
When the piano key is 405 Hz and the tuning fork is 402 Hz, then 405 - 402 = 3 beats are heard.
The piano key is 405 Hz.
A scientific theory is different from a hypothesis because a theory is a educated guess that is being worked on and proven correct and a hypothesis is a educated guess it is a guess that needs to be proven.
Answer:
The work done by the force on the particle is 29.85 J.
Explanation:
The work is given by:

Where:
x₁: is the lower limit = 0 m
x₂: is the upper limit = 1.9 m
Fₓ: is the force in the horizontal direction = (4.5 + 13.7x - 1.5x²)N

Therefore, the work done by the force on the particle is 29.85 J.
I hope it helps you!