Suppose, a lighthouse operator (L) observes a fishing boat (B) that is moving straight away from the light house. The level of the lighthouse operator is 20 m above the level of the sea. At a particular instant, the lighthouse operator observe the boat (B1) with a depression angle of 800 . Two minutes later, the boat (B2) was observed with a depression angle of 400 . What is vB, the speed of the boat as measured by the light house operator in m/s

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

less than one you can't create energy

0.11 m/s and 0.28 m/s should be correct