cobra.parkland.edu C 888 + 4 of 15 - + Automatic Zoom > > 1) In order to make car crashes safer, engineers try to minimize the crash's deceleration. In a crash test, a 1.81x103 kg car is driven into a very sturdy wall at 46.4 m/s. If the wall recorded an average force of 3.87x105 N during the collision, then for this test: A) What was the car's initial forward momentum? [kg-m/s] a) +8.40x104 c) +2.10x105 b) -8.40x104 d) -2.10x105 e) None/Zero B) What was the car's final forward momentum? [kg-m/s] a) +8.40x104 c) +2.10x105 b) -8.40x104 d) -2.10x105 e) None/Zero C) What was the impulse vector on the car? [N-s] a) +3.36x104 +8.40x104 b) -3.36x104 d) -8.40x104 e) None/Zero D) What was the duration of the crash? [s] a) +0.217 c) +0.543 b) -0.217 d) -0.543 e) None/Zero E) What was the car's average forward acceleration? [m/s2] a) +85.6 c) +214 b) -85.6 d) -214 e) None/Zerocobra.parkland.edu C 888 + 8 of 15 - + Automatic Zoom > > 3) A bicycle is initially traveling at 6.17 m/s due south. The rider then starts to pedal harder, causing the bike's wheels to angularly accelerate at 3.46 rad/s2 for a duration of 5.44 s If the bike wheels have a radius of 0.297 m, and if "x" = north and "y" = up, then what is: A) the angular acceleration of the bike wheels? [rad/s2] a) +1.38 c) +3.46 b) -1.38 d) -3.46 e) None/Zero B) the final angular velocity of the wheels? [rad/s] a) +15.8 c) +39.6 b) -15.8 -39.6 e) None/Zero C) the final north-south velocity of the bike? [m/s] a) +4.72 C) +11.8 b) -4.72 d) -11.8 e) None/Zero D) the north-south acceleration of the bike? [m/s2] a) +0.412 c) +1.03 b) -0.412 d) -1.03 e) None/Zero E) the north-south displacement of the bike? [m] a) +19.5 c) +48.8 b) -19.5 d) -48.8 e) None/Zerocobra.parkland.edu C 888 + 6 of 15 - + Automatic Zoom D> > 2) A 25.7 kg cart is initially at rest when you push it with a 218. N force, due west. As a result, the cart moves 6.02 m due west. If friction effects are negligible, then: A) What is the work done by the push? [J] a) +524 c) +1.31x103 b) -524. d) -1.31x103 e) None/Zero B) What is the work done by gravity? [J] a) +524 c) +1.31x103 b ) -524. d) -1.31x103 e) None/Zero C) What is the work done by the normal force from the a) +524 c) +1.31x103 floor? [J] b ) -524 d) -1.31x103 e) None/Zero D) What is the final kinetic energy of the cart? [J] a) +524 c) +1.31x103 b ) -524. d) -1.31x103 e) None/Zero E) What is the final speed of the cart? [m/s] a) +4.04 C) +10.1 b) -4.04 d) -10.1 e) None/Zero