Present full solutions on a separate piece of paper. Remember to include units and round final answers to the appropriate number of significant digits. 1. The graph shows the velocity of a motorcycle police officer plotted as a function of time. Find the instantaneous acceleration at time t = 3.0s, at t = 7.0s and at t = 11s. vx (m/s) 50' 45 40 35 30 25 20 15 10 5 0 2 4 6 8 10 12 14 2012 Pearson Education, Inc. >t(s) 2. Small frogs that are good jumpers are capable of remarkable accelerations. One species reaches a takeoff speed of 3.7 m/s in 60 ms. What is the frog's average acceleration during the jump? 3. When jumping a flea rapidly extends its legs, reaching a takeoff speed of 1.0 m/s over a distance of 0.50 mm. Assume constant acceleration. a) What is the flea's acceleration as it extends its legs? b) How long does it take the flea to leave the ground after it begins pushing off? 4. A subway train starts from rest at a station and accelerations at a rate of 1.60 m/s for 14.0 s. It runs at constant speed for 70.0 s and slows down at a rate of 3.50 m/s until it stops at the next station. Find the total distance covered. 5. A football is kicked straight up into the air; it hits the ground 5.2 s later. a) What is the greatest height reached by the ball? Assume it was kicked from ground level. b) With what speed did it leave the kicker's foot? 6. Let A = (3.0 m, 20 South of East), B = (2.0 m, North), and C = (5.0 m, 70 South of West). a) Draw and label A, B, and C with their tails at the origin. Use a coordinate system with the x-axis to the East. b) Write the x- and y- components of vectors A, B, and C. c) Find the magnitude and direction of D = A + B + . 1