मूल बिंदु पर स्थित 2 × 10-9 m3 के एक वृद्धिशील आयतन (incremental volume) में घिरा कुल आवेश ______ nC है, यदि इसके क्षेत्र का विद्युत प्रवाह घनत्व D = e-x sin(y) i - e-x cos(y) j + 2z k C/m2 के रूप में दिया गया है।

Two objects of masses 80 kg and 250 kg are placed 200 m apart. What is the gravitational force between them? (Take G = 6.7 × 10-11 N·m2/kg2)

In an experiment, 25 g of reactant A reacts completely with 35 g of reactant B to form 50 g of product C and some amount of product D. Based on the law of conservation of mass, what is the mass of product D?