On an ice skating rink, a girl of mass 50. kg stands stationary, face to face with a boy of mass 80. kg. The children push off of one another, and the boy moves away with a velocity of -4.0 m/s. To two significant digits (the tenths place), what is the final velocity of the girl? m/s

Lx bxh

This is the answer: body 1 + engine 2

Answerthe energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.explanationwe define electric potential as the ratio electric potential energy to the charge,    then the following gives us the potential difference,      the formula  may be on your formula sheet.the change in electric potential energy would be the energy that would needed to move it from point a to point b. solving for that, we get    using q = 8.00  × 10⁻¹⁹ c and  δv = 2.00 v, we get    the energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.