<h2>Option 1 is correct option .</h2>
Explanation:
The velocity of sound depends upon temperature . The temperature is different at different altitudes .
The velocity of sound has no effect of pressure . Thus at different altitudes , if pressure is different , it makes no difference .
Therefore the speed of sound varies rapidly with altitude , due to variation of temperature .
It also depends on the nature of medium . which also varies with altitude .
Moreover we cannot get distance by dividing time interval with 3 .
Answer:
a) 0.78 s
b) 58.86m/s'
c) Galileo's law of free fall
Explanation:
a) 
b)At the bottom:
kinetic energy = potential energy
downwards
c) Galileo's law of free fall says regardless of the masses, bodies in a vacuum will fall, on the earth, at the same acceleration
The development of the microscope, a key innovation in the field of technology, lead to the development of Cell Theory, a key innovation in the field of science.
Similar elements with similar properties were in the same groups and periods for instance lithium(Li) and sodium(Na) are alkaline metals and so belong to the same group (that is group 1).Also Hydrogen(H) and Helium(He) both have only one shell or energy level and so belong to the same period.
Electricity. Ruler. 69. N.