7. A 1500-m-wide dam holds back a lake 95 m deep. The torque that the water exerts about the bottom edge of the dam is(A) 2.1×10¹² N·m(B) 1.3×10¹¹ N·m(C) 2.1×10¹⁰ N·m(D) 1.3×10¹⁰ N·m(E) 2.1×10⁹ N·m

5. A parallel plate capacitor, with air dielectric, is charged by a battery after which the battery is disconnected. A slab of glass dielectric is then slowly inserted between the plates. As it is being inserted,(A) a force repels the glass out of the capacitor.(B) the glass makes the plates repel each other.(C) no force acts on the glass.(D) a net charge appears on the glass.(E) a force attracts the glass into the capacitor.

7. A 1500-m-wide dam holds back a lake 95 m deep. The torque that the water exerts about the bottom edge of the dam is
(A) 2.1×10¹² N·m
(B) 1.3×10¹¹ N·m
(C) 2.1×10¹⁰ N·m
(D) 1.3×10¹⁰ N·m

(E) 2.1×10⁹ N·m

相關試題

相關試卷