Pls help as soon as possible

Work = force × a. work b. energy c. distance d. momentum

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight

A6.0-μf air-filled capacitor is connected across a 100-v voltage source. after the source fully charges the capacitor, the capacitor is immersed in transformer oil (of dielectric constant 4.5). how much additional charge flows from the voltage source, which remained connected during the process?