Answer: Option (B) is correct.
The first law of thermodynamics is an adaptation of the law of conservation of energy, this is thoroughly adapted for the systems(thermodynamics). Law of conservation of energy defines that the total energy of a confined system is stable; energy can be transferred or converted from one form to another, but it cannot be formed or destroyed.
The potential energy will increase
The speed of both cars is the same ... 80 km per hour.
But their velocities are different, because DIRECTION is part of velocity, and their directions are different.
So the formula for density is mass divided by volume, so it would be
