!!! Draw (T) A a Ask Copilot + 1 of 3 RE 1311 Midterm (multiple choice questions) 1) The velocity vector of a particle in a 3-dim space is defined as a) The arrow that goes from the origin of coordinates to the particle b) The temporal derivative of the position vector c) None of the previous 2) The acceleration vector of a particle in a 3-dim space is defined as a) The arrow that goes from the origin of coordinates to the particle b) The temporal derivative of the position vector c) The temporal derivative of the velocity vector d) None of the previous 3) In a constant acceleration motion a) The jerk vector is null. b) The velocity vector is = +a(t-to) c) The position vector is = +(t to)+ )+ (t1) d) All of the above 4) The first Newton's Law establishes a) If not net force acts on a particle, its acceleration is null. b) If a net force acts on a particle, it will oppose the action. c) If a force acts on a particle, its speed becomes constant. d) None of the above 5) Friction forces are: a) Conservative b) Non-conservative c) They can be derivated from a potential energy. 1 50 0 !!! Draw (T) A a Ask Copilot + 2 of 3 ( e d) None of the above 6) The Third Newton's Law a) applies only to bodies in a vacuum. b) is always true for the interactions among particles. c) is equivalent to the Second Newton's law d) none of the above 7) The international unit of energy is: a) Newton b) Joule c) Watt d) Ampere 8) Is Gravity a a) conservative force? b) non-conservative force? c) both, conservative and non-conservative? 9) The dynamical definition of a force applied on a particle is: a) F=m b) F=mv c) None of the above 10) Kinetic Energy is defined as a) K = 1 b) K = my c) All of the above 2 K 0 0 0 !!! Draw (T) A a Ask Copilot + 3 of 3 C CD RE 1311 Midterm Problems (3) 1) A 65-kg person walks towards a 150-kg wagon and jumps into it. The velocity of the person immediately before jumping was 2 m/s when the wagon was moving in the same direction at 1 m/s. Calculate the final velocity of the system (person plus wagon). 2) What Earth's moment of inertia around its rotation axis? What is its angular momentum? Make the calculations using the formula in lecture II.15 (Please, google the necessary data). 3) For the GE 1.5 MW wind turbine described by the following table check the validity of the formula for torques: THSS = &GB LSST LSS @HSS (Remember, HSS states for High-Speed Shat, and LSS for Low-Speed Shaft) GE 1.5 MW wind turbine specifications: Power (kW) 1664 20 Low-Speed Shaft Speed 2.09 794,501 High-Speed Shaft Torque Efficiency Power Speed (rpm) (rad/sec) (N-m) (kW) (rpm) (rad/sec) 1631 1440 Gearbox Gen-PE Output Torque Efficiency Power (N-m) (kW) 0.98 151 10,814 0.92 1500 3 GE-1.5-PwrCurve1.xls Rev 08 Dec 04 K 0 0 0