This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: This printout should have 13 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 001 10.0 points An airplane of mass 998 kg flies level to the ground at a constant speed of 175 m / s relative to the Earth. An observer on the ground along the path of the plane sees the plane a distance 13003 . 7 m away at an angle above the horizontal of 57 . 77 . What is the magnitude of the airplanes angular momentum relative to a ground ob server directly below the airplane? Correct answer: 1 . 92115 10 9 kg m 2 / s. Explanation: Basic Concepts: vector L = vector r vector p L = r mv sin( ) = (13003 . 7 m)(998 kg)(175 m / s) sin(57 . 77 ) = 1 . 92115 10 9 kg m 2 / s 002 (part 1 of 2) 10.0 points Given: Use counterclockwise as the positive angular direction. The acceleration of gravity is 9 . 8 m / s 2 . A particle of mass m is shot with an initial velocity 2 m / s, making an angle 46 , with the horizontal as shown in figure. The particle moves in the gravitational field of the Earth. x y v R v o 2 m / s v o v h 46 R h O C A Using the origin as the pivot, find the an gular momentum (along the zaxis, using a righthand coordinate system) when the par ticle is at the highest point of the trajectory. Correct answer: . 440144 N m. Explanation: Basic Concepts vector L = vectorr vectorp vector L = I vector We also need the vector cross product  vectora vector b  = a b sin , where is the angle between the vectors vectora and vector b . Let : v o = 2 m / s , = 46 , and g = 9 . 8 m / s 2 . Solution: At the highest point (denote the position vector to that point with vector r h ) we know that vector v h = vector v x = v o cos and vector L = vector r h vector p h = vector r h m vector v h And,  vector L  = m  vector v h  vector r h  sin h . Let us analyze this expression. We see that vector r h sin h is the maximum height of y max = h h =  vector r h  sin h = v o 2 sin 2 2 g ....
View
Full
Document
 Spring '08
 Turner
 Mass, Work

Click to edit the document details