Answer Happy

1- If C = -3î – 2ſ – 4k what is Č xſ? A) +4î – 3 B) +3î – 4Ń C) -3 - 4k D) +4 + 2ị – 3 E) -3î – 2ſ + 4Ń 2- Two objects are dropped from a bridge, an interval of 1.0 s apart, and experience no appreciable air resistance. As time progresses, the DIFFERENCE in their speeds A) increases. B) decreases. C) increases at first, but then stays constant. D) remains constant. E) decreases at first, but then stays constant. 3- A ball is tied to the end of a cable of negligible mass. The ball is spun in a circle with a radius 2.00 m making 4.00 revolutions every 10.0 seconds. What is the magnitude of the acceleration of the ball? A) 19.7 m/s B) 28.4 m/s? C) 50.5 m/s2 D) 38.7 m/s2 E) 12.6 m/s? 4- Puck slides a total of 12 m before coming to rest. If the coefficient of kinetic friction between the puck and the horizontal board is 0.18, what was the initial speed of the puck? A) 10.6 m/s B) 9.5 m/s C) 6.5 m/s D) 8.1 m/s E) 11.7 m/s