Control rods<span> are </span>rods<span>, plates, or tubes containing a neutron absorbing material (material with high absorbtion cross-section for thermal neutron) such as boron, hafnium, cadmium, etc., used to </span>control<span> the power of a nuclear reactor.
so the statement that describe a control rod is:
</span><span>Control rods are lowered into the reactor to slow down the reaction by absorbing neutrons.</span>
Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.
I can confirm, your answer is 800J (Or 800 Joules)!
I just took the test and this was the correct answer :)

where:
F - force
m - mass
a - acceleration
We transform this formula to get a:

Answer:
B. interactive
Explanation:
newtons first law is inertia his second is acceleration and third is interactive.