1) When the friction less system shown above is accelerated by an applied force of magnitude the tension in the string between the blocks is (A) 2F (B) F (C) 2/3 F (D) 1/3 F 2) A block of mass 5 kilograms lies on an inclined plane, as shown below. The horizontal and vertical supports for the plane have lengths of 4 meters and 3 meters, respectively. The coefficient of friction between the planeand the block is 0.3. The magnitude of the force F necessary to pull the block up the plane with constant speed's most nearly (A) 30 N (B) 42 N (C) 49 N (D) 50 N
3 )The position of a toy locomotive moving on a straight track along the x-axis is given by the equation x = t3-6t2+ 9t, where x is in meters and t is in seconds. The net force on the locomotive is equal to zero when t is equal to (A) zero (B) 2 s (C) 3 s (D) 4 s
What is the acceleration of the block? (A) F/m (B) (Fcosφ)/m (C) (F-f)/m (D) (Fcosφ-f)/m