Questions 4 5: A cart is constrained to move along a straight line_ A varying net force along the direction of motion is exeited on the can. The cart's velocity v as a function of time t is shown in the graph The live labeled points divide the graph into four sections. 4.1 Which of the following correctly ranks the magnitude of the average acceleration of the cart during the four sections of the graph? (A) aco > ass > aec > ace (B) 33c > am > ace > ace (C) 3A3 > aec > ace > ace (D) am > 6.48 > aDE > aec The correct answer is What feature ofthe graph did you use to determine the average accelerations?1 4.2 For which segment does the cart move the greatest distance? (A) AB (B) BC (C) CD (D) DE The correct answer is What feature ofthe graph did you use to determine the distances? 4.3A motorist travels 320 km at 80 kmh and then 320 km at 100 km/h. The average speed of the motorist for the entire trip is most nearly equal to... A) 84 kah B) 89 km/h C) 90 km/h D) 91 kmfh The correct answer is How can you arrive at this conclusion without doing a full calculation?. 5. AP Physics B EXAM 1994 Question B1. Sin 370 = 0.60 Plane of A ball of mass 0.5 kilogram, initially at Cos 37 = 0.80 Fence Tan 370 = 0.75 Fence rest, is kicked directly toward a fence from a point 32 meters away, as 20 m/s shown above. The velocity of the ball 2.5 m as it leaves the kicker's foot is 20 meters per second at an angle of 37 32 m above the horizontal. The top of the Note: Diagram not drawn to scale. fence is 2.5 meters high. The kicker's foot is in contact with the ball for 0.05 second. The ball hits nothing while in flight and air resistance is negligible. a. Calculate the magnitude of the average net force exerted on the ball during the kick. b. Calculate the time it takes for the ball to reach the plane of the fence. c. Will the ball hit the fence? If so, how far below the top of the fence will it hit? If not, how far above the top of the fence will it pass? d. On the axes below, sketch the horizontal and vertical components of the velocity of the ball as functions of time until the ball reaches the plane of the fence. 201 Horizontal Vertical Component of Velocity OF + Time (s) Component 4.0 of Velocity OF *+ Time (s) (m/s) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 (m/s) 3.0 3.5 4.0 -st- -101-- -15- -20 In the above question what is the velocity at the top of the trajectory in terms of V. and 0