Chapter 7 C1. The volume of the solid formed by revolving the region bounded by the graph of y x 3 and the coordinate axes about the x-axis is given by which of the following integrals? 2 3 A x 3 3 2 B x 3 dx 0 9 4 0 dx C x 3 9 4 dx 0 D 2 x x 3 0 3 2 dx E 2 x x 3 4 dx 0 C2. The region in the first quadrant enclosed by the graphs of y=x and y=2sinx is revolved about the x-axis. The volume of the resulting solid figure is (A) 1.895 (B)2.126 (C)5.811 (D)6.678 (E)13.355 C3. The region enclosed by the line x+y=1 and the coordinate axes is rotated about the line y=-1. What is the volume of the solid generated? 17 17 2 3 4 ( A) ( B) (C ) ( D) (E) 2 4 3 4 3 C4. The region R enclosed by the coordinate axes and the graph of y k x 2 is shown below. When this 2 y region is revolved around the y-axis, the solid formed has a volume of 8 cubic units. What is the value of k? A 1 D 2 4 3 E3 B C 3 y=k(x-2)2 R x NC 5. A solid has a circular base of radius 3. If every plane cross section perpendicular to the x-axis is an equilateral triangle, then its volume is ( A) 36 ( B)12 3 (C )18 3 ( D) 24 3 ( E ) 36 3 C6. The base of a solid is the region enclosed by the coordinate axes and the graph of y 3 x 2 . If every cross section perpendicular to the x-axis is a square then the volume of the solid is (A) 8.0 (B)19.2 (C)24.0 (D)25.6 (E)57.6 2 NC 7. The velocity of a particle moving along the y-axis is given by v(t)=8-2t for t>0. The particle moves upward until it reaches the origin and them moves downward. The position of the particle at any time t is given by ( A) t 2 8t 16 ( B) t 2 8t 16 (C )2t 2 8t 16 ( D)8t 2t 2 ( E )8t t 2 NC 8. A particle moves on the x-axis in such a way that its position at time t is given by x(t ) 3t 5 25t 3 60t. For what values of t is the particle moving to the left? (A) –2<t<1 (B)-2<t<-1 and 1<t<2 (C)-1<t<1and t>2 (D) 1<t<2 (E) t<-2, -1<t<1, and t>2 NC 9. Which graph best represents the position of a particle, s(t) as a function of time, if the particle’s velocity and acceleration are both positive? s(t) s(t) s(t) s(t) s(t) A B C D E 1 x NC 10. A particle moves along the x-axis so that at any time t its position is given by (t ) sin t cos(2t ). 2 What is the acceleration of the particle at t ? 2 1 3 5 7 ( A) 0 ( B) (C ) ( D) (E) 2 2 2 2 t t t t t