Which correctly identifies the distribution of elements in the universe?
a. the universe is 70% hydrogen and 2% heavy elements.
b. the universe is 80% hydrogen and 9% oxygen.
c. the universe is 90% heavy elements and 4% hydrogen.
d. the universe is 95% heavy elements and 2% oxygen.?

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?