How do rocks record changes in earths magnetic field

Acapacitor is storing energy of 3 joules with a voltage of 50 volts across its terminals. a second identical capacitor of the same value is storing energy of 1 joule. what is the voltage across the terminals of the second capacitor?

Suppose astronomers built a 140-meter telescope. how much greater would its light-collecting area be than that of the 10-meter keck telescope? express your answer using two sign

Hunter’s velocity was 4.5 m/s. at the end of his race, his velocity was the same. which best describes his movement? his movement stopped. his acceleration is zero. his time was constant. his acceleration was positive.