Answer: Electromagnetism and sound
The correct answer to the question is : D) Be moving at a constant velocity.
EXPLANATION:
As per Newton's first laws of motion, every body continues to be at state of rest or of uniform motion in a straight line unless and until it is compelled by some external unbalanced forces acting on it.
Hence, it is the unbalanced force which changes the state of rest or motion of a body. Balanced force is responsible for keeping the body to be either in static equilibrium or in dynamic equilibrium.
As per the options given in the question, the last one is true for an object under balanced forces.
D. Velocity because it describes a speed and direction
145 Grams!
It asks for the “Total Mass” basically asking to add, If you add 20 to 125, you get 145! Correct me if im wrong
Answer:
Explanation:
Given
Distance between two loud speakers 
Distance of person from one speaker 
Distance of person from second speaker 
Path difference between the waves is given by

for destructive interference m=0 I.e.




frequency is given by

where 

For next frequency which will cause destructive interference is
i.e.
and 


frequency corresponding to this is

for 


Frequency corresponding to this wavelength
