<h3>During a chemical reaction,one ore more new substances forwed</h3>
If
and
are perpendicular, then their dot product is zero. This means

Solving for n is trivial; it follows that n = 3.
Answer:
Work done is zero
Explanation:
given data
Angle of kite with horizontal = 30 degree
tension in the string = 4.5 N
WE KNOW THAT
Work = force * distance
horizontal force = 
DISTANCE = 0 as boy stands still. therefore
work done = 3.89 *0 = 0
it is generated by two objects pushing against each other with equal/almost equal force, therefore contracting against each other