Answer the questions with completed solutions. 11A car travels in a straight line with an average velocity of 80.0 km/h for 2.50 h and then With an average velocrty of 40.0 km/h for 1.50 h. (a) What is the total displacement for the 4.00 h trip? (b) What IS the average velocity for the total trip? 2. A train started from rest and moved with constant acceleration. At one time it was traveling 30 m/s, and 160 m farther on it was traveling 50 m/s. Calculate (a) the acceleration, (b) the time required to travel the 160 m mentioned, (0) the time required to attain the speed of 30 m/s, and (d) the distance moved from rest to the time the train had a speed of 30 m/s. (e) Graphx versus 1 and v versus 1 for the train, from rest. 3. Two subway stops are separated by 1100 m. If a subway train accelerates at +1.2 m/s2 from rest through the rst half of the distance and decelerates at 1.2 m/s2 through the second half, what are (a) its travel time and (b) its maximum speed? (c) Graph x, v, and a versus 1 for the trip. ' 4. The Zero Gravity Research Facility at the NASA Glenn Research Center includes a 145 m drop tower. This is an evacuated vertical tower through which, among other possrbilities, a l-m- diameter sphere containing an experimental package can be dropped. (a) How long is the sphere in free fall? (b) What is its speed just as it reaches a catching device at the bottom of the tower? (c) When caught, the sphere experiences an average deceleration of 25g as its speed is reduced to zero. Through what distance does it travel during the deceleration? 5. A police car chases a speeder who is travelling at 125 km/h The maximum speed of the police car is 190 km/h. The police car travels from rest with a constant acceleration of 8.00 km/h-s until its speed reaches 190 km/lL It then moves at constant speed. (a) When does the police car catch the speeder if it starts just as the spwder passes? (b) How far has each car travelled? (0) Sketch x(t) for each car. 6. A proton moves along the x axis according to the equation x = 50! + 1012, where x is in meters and t is in seconds. Calculate (a) the average velocity of the proton during the rst 3.0 s of its motion, (b) the instantaneous velocity of the proton at t = 3.0 s, and (c) the instantaneous acceleration of the proton at t = 3.0 s. (d) Graph x versus t and indicate how the answer to (a) can be obtained from the plot. (e) Indicate the answer to (b) on the graph (t) Plot v versus 1 and indicate on it the answer to (c). 7. Two particles move along an x axis. The position of particle l is given by x = 6.00t2 + 3001' + 2.00 (in meters and seconds); the acceleration of particle 2 is given by a = 8.00t (in meters per second squared and seconds) and, at I = 0, its velocity is 20 m/s. At the instant when the velocities of the two particles are the same, what is their common velocity? ne, starting from rest, with constant acceleration. direction of the acceleration, while keeping its to get back to the startlng 8. A ladybug runs along a straight li After time 1, the ladybug reverses the magnitude the same. How long (T) would it take for the bug point, from the time that it started running