<span>Sound waves with frequency higher that 20,000 Hz are referred to as "Ultrasonic"
Hope this helps!</span>
Answer with Explanation:
We are given that
A=3i-3j m
B=i-4 j m
C=-2i+5j m
a.


Compare with the vector r=xi+yj
We get x=2 and y=-2
Magnitude=
units
By using the formula 
Direction:
By using the formula
Direction of D:
b.E=-A-B+C


units
Direction of E=
v is velocity, x is position, t is time, and a is acceleration.
Ans) A) Centripetal force will be doubled.
See centripetal force F = mv^2/r
That means centripetal force is directly proportional to the mass of the particle
So, if we double the mass, centripetal force will be increased by twofolds.
So, option A) is correct.
Now, looking at the other options,
B) says centripetal force is unaltered which is incorrect as centripetal force has been altered and increased twofold.
Option C) and D) reduces centripetal force which are also not possible here.
So, only Option A) is correct
Answer:
no force exists by itself because every action has an equal and opposite reaction