Answer:
70.07 Hz
Explanation:
Since the sound is moving away from the observer then
and 
when moving towards observer
With 
of 76 then taking speed in air as 343 m/s we have
Similarly, with of 65 we have
Now
v_s=27.76 m/s
Substituting the above into any of the first two equations then we obtain
Explanation:
By the statement, Efficiency of a machine is 60% it is meant that 'The work output is 60% of the work input'. If you apply 100J of energy for a machine, it will be able to life load of 60 J only
-- water shooting out of a hose
-- writing an email
-- making hard-boiled eggs
-- driving to the dentist
-- the emission spectrum of a carbon arc
-- buying a new car
-- putting your shoes on
-- singing a song
-- cutting a tree down
-- learning to dance
-- cleaning the windows
-- building a radio
-- ironing your shirt
-- riding a bicycle
-- playing the piano
A. a steel beam. All of the rest of them change shape or volume whereas a steel beam with never change in volume or shape.
On the surface of the earth, weight is calculated by multiplying mass
and gravity.
<span>Because we know the radius of the Earth, we can use the Law of
Universal Gravitation to calculate the mass of the Earth in terms of the
gravitational force on an object (its weight) at the Earth's surface, using the
radius of the Earth as the distance. We also need the Constant of
Proportionality in the Law of Universal Gravitation, G. This value was experimentally determined by Henry
Cavendish in the 18th century to be the extemely small force of 6.67 x 10</span>-11 Newtons
between two objects weighing one kilogram each and separated by one meter.
Cavendish determined this constant by accurately measuring the horizontal force
between metal spheres in an experiment sometimes referred to as "weighing
the earth."
The correct answer between all
the choices given is the third choice or letter C. I am hoping that this answer
has satisfied your query and it will be able to help you in your endeavor, and
if you would like, feel free to ask another question.
