Answer:
Rod 1 has greater initial angular acceleration; The initial angular acceleration for rod 1 is greater than for rod 2.
Explanation:
For the rod 1 the angular acceleration is
Similarly, for rod 2

Now, the moment of inertia for rod 1 is
,
and the torque acting on it is (about the center of mass)

therefore, the angular acceleration of rod 1 is


Now, for rod 2 the moment of inertia is


and the torque acting is (about the center of mass)


therefore, the angular acceleration
is


We see here that

therefore

In other words , the initial angular acceleration for rod 1 is greater than for rod 2.
Answer:
d. all of the above
Explanation:
a) Absolute dating technique is used to determine the age of rocks and fossil fuels, by the use of radioactive elements, such as, Carbon-14. The process involves the measurement of life of fossils through the remaining amount of radioactive element. It is possible by the knowledge of half life of radioactive element.
b) The radioactive isotope of Cobalt (Cobalt-60) is used to treat localized cancer. Other radioactive elements are also used to kill bacteria and treat cancer, such as, Iodine-131 is used to treat thyroid cancer
c) Radioactive elements are also used as tracers, such as Sodium-24, which is used as a tracer in blood. Other radioisotopes of Hydrogen, Carbon. Phosphorus and Sulfur, etc, are also used as tracers in different chemical reactions.
<u>Thus, all the given options are correct and the correct option is all of the above (d).</u>