Cracking the SAT Physics Subject Test

(B)

(C)

(D) 2λ

(E) 4λ

58. Lead-199 has a half-life of 1.5 hours. If a researcher begins with
    2 grams of lead-199, how much will remain after 6 hours?

(A) 0.125 grams

(B) 0.25 grams

(C) 0.375 grams

(D) 0.5 grams

(E) 0.625 grams

59. The square shown is the same size in each of the following
    diagrams. In which diagram is the electrical potential energy of the
    pair of charges the greatest?

(A)

(B)