work done=446.9 J . so option (c) is correct.
Explanation:
the formula for work done is given by
W= F d
F= force= mg where m= mass and g= acceleration due to gravity
F= 3.8 (9.8)=37.24 J
so W=37.24 (12)
W=446.9 J
Yes. Think of block sitting on top of a bigger block. If the bottom block moves, it will drag the top block with it. Since the force of friction on the small block and its displacement are in the same direction, the "work" is positive. The static friction is a passive force, It is not a source of energy; it transmits the force placed on the bottom block. (And the "work" done by the friction on the bottom block is exactly the negative of the work done on the top block.)
I googled the specific heat capacity for iron so it might be off to the value you might have used, bit it should be close.
The unknown liquid has low H+ concentrations and high OH- concentrations.
The forces in some car crashes are greater than others; therefore, the body can be more severely injured by greater and more powerful forces. I hope this helped! :^)
