o sursa luminoasa punctiforma se afla pe axul optic al unei lentile cu distanta focala f=3cm la distanta x1=4cm de centrul optic alacesteia . De cealalta parte, la d=3cm, se afla o lentila identica cu prima. Cele doua lentile au acelasi ax optic. Unde se va forma imaginea sursei de lumina?

Consider two metallic rods mounted on insulated supports. one is neutral, the other positively charged. you bring the two rods close to each, but without contact, and briefly ground the the neutral rod by touching it with your hand. show answer correct answer what would be resulting charge (if any) on the initially neutral rod

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity