4. [-/0.69 Points] DETAILS SCALCET9 12.3.052. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A boat sails south with the help of a wind blowing in the direction $36'E with magnitude 500 lb. Find the work (in ft-lb) done by the wind as the boat moves 140 ft. (Round your answer to the nearest whole number.) ft - lb Need Help? Read It 5. [-/0.69 Points] DETAILS SCALCET9 12.4.035. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Find the volume of the parallelepiped with adjacent edges PQ, PR, and PS. P(-2, 1, 0), Q(5, 2, 5), R(1, 4 , -1 ), S( 3 , 6 , 3 ) cubic units Need Help? Read It Watch It 6. [-/0.69 Points] DETAILS SCALCET9 12.4.053. MY NOTES ASK YOUR TEACHER Suppose that a # 0. (a) If a . b = a . c, does it follow that b = c? O Yes O No (b) If a x b = a x c, does it follow that b = c? Yes O No (c) If a . b = a . c, and a x b = a x c, does it follow that b = c? Yes O No Need Help? Read It Watch It 7. [-/0.69 Points] DETAILS SCALCET9 12.5.004. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Find a vector equation and parametric equations for the line. (Use the parameter t.) the line through the point (7, 0, -3) and parallel to the line x = 4 - 4t, y = -1 + 2t, z = 6 + 9t r(t) = (x(1). y(1). z(1) ) = Need Help? Read It 8. [-/0.69 Points] DETAILS SCALCET9 12.5.064. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Find the point at which the given lines intersect. r = (2, 3, 0) + t(3, -3, 3) r = (5, 0,3) + s(-3, 3, 0) (x. y. z) = (b) Find an equation of the plane that contains these lines