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RP9-1) The impulse-momentum principle is mostly used for solving problems involving what parameters?
RP9-2) The linear impulse-momentum principle is derived by integrating Newton’s second law with respect to time.
RP9-3) If the mass of a particle doubles, then its linear momentum and kinetic energy also both double.
RP9-4) The impulse applied to a particle by a force is
RP9-5) A particle, initially at rest, is acted upon by a time-varying force F(t). Rank the following force profiles from greatest to least achieved particle speed.
Ranked from greatest to least.
RP9-6) Conservation of linear momentum of a particle over a period of time requires that
RP9-7) If linear momentum is conserved in one component direction then it also must be conserved in the perpendicular component direction.
RP9-8) Which quantities are in general conserved during a collision between multiple particles?
RP9-9) Both linear momentum and energy are conserved during which type of collision?
RP9-10) A rocket is propelled by expelling high-velocity gas. The resulting motion is a consequence of which of the following.
RP9-11) Consider two cases of the following situation. You need to push a broken down car back to town. First, you push the car starting from rest with a constant force F for 1 minute. Second, you push the car already rolling at 3 mph with a constant force F for 1 minute. In which case does the car experience a larger change in momentum? In both cases, assume that the ground is level and friction is negligible.
RP9-12) Why does an egg crack when tossed against a brick wall but not when tossed against a taut bed sheet?
RP9-13) If the mass of a particle doubles, then its linear momentum and angular momentum also both double.
RP9-14) Which of the following quantities of a particle are dependent on the particle’s position?
RP9-15) Which is the correct formula for the angular momentum of a particle?
RP9-16) The angular momentum of a particle can be conserved over an interval of time where the external forces applied to the particle do not sum to zero.
RP9-17) A 1.4-kg toy rocket is initially resting on the ground when its engine is fired causing the rocket to travel vertically upward. The thrust generated by the rocket's engine is given in the attached graph. If the engine's maximum thrust is 30 N, determine the rocket's maximum velocity. Assume that air resistance is negligible.
RP9-18) Three train cars are rolling along a horizontal track. The velocities of car A, B and C are 3, 2 and 1 mph, respectively, in the directions shown. The weights of car A, B and C are 140, 30 and 100 tons, respectively. After the cars collide they couple and move with a common velocity. Determine the cars' final velocity and the percentage of energy that is lost in the collision.
RP9-19) Two identical hockey pucks sliding on ice, with the velocities and directions shown, collide. If the coefficient of restitution is e = 0.8, determine the velocities after impact and the energy lost during the collision.
RP9-20) Two 1-kg masses are attached to light bars of length L = 1.2 m which are fixed to a rotating shaft. The shaft is initially rotating at 10 rad/s when a 2-N-m moment is applied in the same direction as the initial rotation. Determine the velocity of the masses 20 seconds after the moment is applied.
RP9-21) A balance pivots freely about O. The balance consists of a 300 mm long weightless arm (l1 = 100 mm, l2 = 200 mm) , a 5-kg sphere (A) and a 1-kg cup (C) and is initially rotating at 10 rad/s in the counterclockwise direction. Block B (7 kg) is dropped from rest at a height of h = 150 mm directly above cup C. The drop is timed such that block B hits cup C when the balance arm is horizontal. Determine the angular velocity of the balance immediately after block B lands in cup C.
