Two parallel plates, each having area a = 3490cm2 are connected to the terminals of a battery of voltage vb = 6 v as shown. the plates are separated by a distance d = 0.36cm. you may assume (contrary to the drawing) that the separation between the plates is small compared with either linear dimension of the plate. a dielectric having dielectric constant κ = 3.6 is now inserted in between the plates of the capacitor as shown. the dielectric has area a = 3490 cm2 and thickness equal to half of the separation (= 0.18 cm) . what is the charge on the top plate of this capacitor?

After the near spacecraft passed mathilde, on several occasions rocket propellant was expelled to adjust the spacecraft's momentum in order to follow a path that would approach the asteroid eros, the final destination for the mission. after getting close to eros, further small adjustments made the momentum just right to give a circular orbit of radius 45 km (45 × 10^3 m) around the asteroid. so much propellant had been used that the final mass of the spacecraft while in circular orbit around eros was only 545 kg. the spacecraft took 1.04 days to make one complete circular orbit around eros. calculate what the mass of eros must be.

Jessie ran 5000 meters from the cops and an average speed of 6 meters / second before he got caught . how long did he run?

Sobre transformações cíclicas, são feitas algumas afirmações, determine quais estão corretas. i – a variação de energia interna em uma transformação cíclica é nula; ii – o trabalho, em uma transformação cíclica, é sempre positivo; iii – ao completar um ciclo, o gás tem a mesma temperatura com a qual começou a transformação; iv – uma transformação cíclica é, obrigatoriamente, composta de transformações conhecidas, como adiabática, isocórica, etc: a) i e iii b) i e ii c) ii e iii d) i e iv e) iii e iv