In the air, there's nothing holding the body of the helicopter still - so the rotor blades spin one direction, but the torque applied to spin the rotors tries to spin the body of the helicopter in the opposite direction. The little rotor on the tail helps keep the body of the helicopter pointed in the same direction.
1. How many beats can be heard by sounding together two tuning forks of frequencies 250Hz and 256Hz?
Number of beats (n) =f2- f1
= 256 - 250
= 6 beats /sec
The two vectors (say A and B) of different magnitudes cannot be combined to give zero resultant since minimum value of combination is ІA-BІ which is not zero if AB.
The three vectors A, B and C of different magnitudes can be zero such that they form a closed triangle, then,
A+B+C=0
or, C=-(A+B)
Hence, the sum of three vectors may be zero if vector sum of any two vectors is equal and opposite to the third vector.
Note: The vectors can give this result only if...
Quality of life refers to the overall well-being, satisfaction, and happiness that an individual or a community experiences in various aspects of their lives.