Question

Choose the Correct answer: 1. A vector A with magnitude 25.0 m points along the positive y direction. If it is rotated by 50.0 degrees counterclockwise, what are the components of the vector? (a) Ax 25.0 cos 50.0° and Ay 25.0 sin 50.0 (b) Ax 25.0 cos 140° and Ay 25.0 sin 140 (c) Ax 25.0 sin 140° and Ay 25.0 cos 140 (d) Ax- 25.0 tan 50.0° and Ay 25.0 sin 50.0° 2. Vector A→points along the y axis with length 5.0, vector B→ makes an angle of 55° with respect to the x-axis and has a length of 7.0. What is the length of vector A-+B- 55° (a) 8.6 (b) 9.3 (c) 11 (d) 12 (e) 15

Answer 1

A_x = A cos (90 degree + 50 degree) = A cos 140 degree = 25 cos 140 degree A_y = A sin (90 + 50) = A sin 140 degree = 25 sin 140 degree option B correct. B_x = B cos 55 degree = 7 cos 55 degree = 4.015 B_y = B sin 55 degree = 7 sin 55 degree = 5.734 R = squareroot B_x^2 + (A + B_y)^2 = squareroot (4.015)^2 + (5 + 5.734)^2 = 11.46 Tilde equal 11 option c correct.