Mass driver constrained by a limited amount of onboard spacecraft power. Thrust and momentum from exhaust, per unit mass expelled, scales up linearly with its velocity (momentum = mv), yet kinetic energy and energy input requirements scale up faster with velocity squared (kinetic energy = mv). Too low exhaust velocity would excessively increase propellant mass needed under the rocket equation, with too high a fraction of energy going into accelerating propellant not used yet. Higher exhaust velocity has both benefit and tradeoff, increasing propellant usage efficiency (more momentum per unit mass of propellant expelled) but decreasing thrust and the current rate of
Mercy Multiplied three financial principles for the program: According to the three guiding principles that founder Nancy Alcorn established, the Mercy Multiplied website states that they do not accept government funding, and as such, are supported solely by donations from individuals, organizations and other ministries. With regard to fund raising events, Mercy Multiplied host gala dinners, Christmas donation drives and running marathons throughout the year, and invite visitors to their website to donate by becoming a financial partner or "sponsoring" a girl. Mercy Multiplied also sell resources to raise funds such as books and sermons by founder Nancy Alcorn, as well as