PHYS 211 Sample Final 1 1 The graph shows the velocities of vehicles A and B as a function of time At t 0 the two vehicles are at the same location i e the same value of x At what future time do vehicle A and vehicle B again have the same value of x i e when does vehicle A catch up to vehicle B A 4 s B 5 s C 2 s D 6 s E 8 s Page 1 PHYS 211 Sample Final 1 A spherical asteroid of mass Mast 1016 kg and radius Rast 10 km moment of inertia Iast 2 4 1023 kg m2 is slowly rotating in free space at an angular velocity of i 6 28 10 4 rad s one revolution every 10 000 seconds around an axis through its center of mass A small comet of mass mc 1011kg and traveling at vi 100 000 m s hits the asteroid at a glancing blow in a direction directly opposing the motion of that part of the asteroid as described in the figure If the comet sticks to the edge of the asteroid embeds itself in it what is the final angular velocity of the composite object vi Rast i A 0 rad s B 8 78 10 4 rad s same rotation direction C 8 78 10 4 rad s opposite rotation direction D 3 78 10 4 rad s same rotation direction E 3 78 10 4 rad s opposite rotation direction Page 2 PHYS 211 Sample Final 1 3 An acrobat leaps from a platform at t 0 At the same moment a second acrobat is fired from a cannon The platform and the cannon are located at the same horizontal position i e the edge of the platform is directly above the mouth of the cannon The solid lines in the figure show the trajectories of each acrobat What condition must be satisfied if the two acrobats are to meet i e collide in mid air A The horizontal components of the velocities of the two acrobats must be the same at t 0 B The vertical components of the velocities of the two acrobats must be the same at t 0 C The velocities of the two acrobats must be the same at t 0 D The speeds of the two acrobats must be the same at t 0 E The acrobat on the platform must jump with a velocity that has zero vertical component Page 3 PHYS 211 Sample Final 1 4 A box is being pulled across a rough surface with non zero coefficient of kinetic friction at a constant velocity by a force Fp that is oriented at an angle of to the horizontal as depicted in the figure What is the magnitude of the force Fp A kmg cos ksin B kmg cos ksin C kmg sin D kmg kcos sin E kmg cos Page 4 PHYS 211 Sample Final 1 5 Consider this mobile in static equilibrium The mobile is made with three masses several massless cords and two rods of negligible mass If the mass labeled C is M what is the mass of B A M 6 B M 2 C M 3 D M E 4M 3 Page 5 PHYS 211 Sample Final 1 A hand pushes horizontally with a constant force on a physics book 6 holding it up against a wall Nothing is moving The coefficient of static friction between the wall and book is s However there is zero static friction between the hand and the book s F hand If the hand suddenly increases its horizontal push to TWICE what it was before what happens to the frictional force of the wall on the book A It doubles B It increases by more than a factor of 2 C It increases but by less than a factor of 2 D It decreases E It stays exactly the same Page 6 PHYS 211 Sample Final 1 7 A uniform sphere of radius R rotates about a diameter with an angular momentum of magnitude L Under the action of internal forces the sphere collapses to a uniform sphere of radius R 2 The magnitude of its new angular momentum is A L 4 B L 2 C L D 2L E 4L 8 A uniform solid disk has a radius of R and mass M and can rotate about a frictionless fixed axle passing through its center perpendicular to the page A force F is applied to the disk s rim as shown with 150 What will the tangential acceleration of a point on the disk s rim be Remember that sin 30 1 2 and cos 30 3 2 A F MR B F M C F 2M D 3 F M E 3 F MR Page 7 PHYS 211 Sample Final 1 9 A 1 kg mass that is moving east at 9 m s collides with a 2 kg mass that is moving north at 6 m s The two masses stick together What is the speed of the resulting 3 kg mass just after the collision A 3 m s B 5 m s C 7 m s D 15 m s E 10 m s Page 8 PHYS 211 Sample Final 1 A flying saucer deep in interstellar space free of external forces and torques 10 rotates about its symmetry axis with angular velocity The aliens inside the saucer rearrange the furniture to make room for a Christmas tree they have just procured from Elvis As a result the angular velocity of the saucer increases to 2 If originally the rotational kinetic energy of the saucer was K after the rearrangement its new rotational kinetic energy is A K 4 B K 2 C K D 2K E 4K Page 9 PHYS 211 Sample Final 1 11 A uniform rectangular block of length 3 m and mass 10 kg sticks out one meter over the edge of a table as depicted in the picture What is the largest mass m that can be hung from the edge of the block by a massless rope for the system to remain in balance i e motionless Choose the closest answer A 30 kg B 20 kg C 5 kg D 10 kg E 40 kg 12 N 6 i8 Nj acts on a particle with position vector r Force F What is the magnitude of the torque on the particle about the origin A 78 Nm B 4 Nm C 76 Nm D 18 Nm E 0 Nm m 6 i5 m j Page 10 PHYS 211 Sample Final 1 13 A satellite of mass Msatellite orbits a planet of mass Mplanet in a circular orbit of radius R What is the speed of the satellite A B C D E 14 An object is fired straight up from the surface of a planet at an initial speed of V The planet has a radius of R and a mass of M The object coasts thereafter and reaches a maximum distance of 2R from the center of the planet before coming to …