Answer:
B
Explanation:
Newton's first law of motion states that a body will remain in its state of rest or if its in motion will continue to move in a straight line, unless its acted upon by an external force.The ability of an object to stay at rest or in motion if its in motion is known as inertia.
Hence the correct option is B.
Answer:
The frequency is 
Explanation:
From the question we are told that
The frequency of the tuning fork is 
The beat period is 
Generally the beat frequency is mathematically represented as
The beat frequency is also represented mathematically as
Where 
is the frequency of the piano
So
the rate of work done or doing work is usually measured by the power of a machine .
Yes, it did help to change the world climate
for example by the Carbon Dioxide released from factories, Cars and even from respiration
