Full Name ______________________________ ACCELERATION PRACTICE PROBLEMS Date ________ Period __________ Seat _____ Use the equations shown in the box to solve the following problems. Be sure to show your work 1. A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, its speed is 4 m/s. But 3 seconds later, at the bottom of the slope, it speed is 22 m/s. What is its average acceleration? a = 2. At the bottom of the slope, the roller coaster is traveling 22 m/s. As it starts up the next hill, gravity causes it to decelerate at a rate of -6.0 m/s 2. After 3.5 seconds of climbing, it reaches the top of the hill. What is its final velocity? ∆t = vf – vo ∆t vf – vo a vf = ( a ∙ ∆t ) + vo vo = vf – ( a ∙ ∆t ) 3. Barely crawling over the second hill at 1.0 m/s, the roller coaster plunges down a very steep slope, accelerating at an average rate of 8.0 m/s 2. At the bottom of the slope it attains a speed of 29 m/s (equal to 65 mi/h). How long did it take for the roller coaster to reach the bottom of the slope? 4. The roller coaster then enters a double loop. When it exits the last loop, it begins decelerating at a constant rate of -3.0 m/s 2, which takes 6.0 seconds to reach the unloading gates and come to a stop. What was the coaster’s original velocity when it exited the loop? 1 Full Name ______________________________ ACCELERATION PRACTICE PROBLEMS 5. Date ________ Period __________ Seat _____ Bob and Ted are having a bicycle race on straight track marked out in meters. Bob is a 6th grader, and Ted is a senior. Since Ted is older and stronger, he allows Bob to build up speed before crossing the starting line. When the race starts, Bob gets his bike up to a top speed of 3 m/s. Ted, starting at rest, begins to peddle when Bob passes him. Ted accelerates at a constant 1.0 m/s 2 until he reaches a top speed of 7 m/s. 1) 2) 3) 4) 5) Use the formulas in the box to help you complete data tables A and B below. Using graph 1, plot distance vs time for both Bob and Ted. Using graph 2, plot speed vs time for both Bob and Ted. Include a legend for each graph, so that Bob’s data can be discerned from Ted’s. For each graph, draw a trend line through the data points. Study the two graphs you made, then answer the following questions: 1) At what distance did Ted finally overtake Bob? Use this formula for table A d = v ∙ ∆t 2) How long into the race did Ted finally overtake Bob? Use these formulas for table B at2 ∆d = 2 3) How fast was Ted going when he finally caught Bob? vf = ( a ∙ ∆t ) + vo 4) At what point in time did Ted reach his top speed of 7 m/s? A B Ted (Acceleration = 1.0 m/s2) Time Distance Velocity (s) (m) (m/s) 0 0 0 1 2 3 4 5 6 7 Bob (Constant speed = 3 m/s) Time Distance Velocity (s) (m) (m/s) 0 0 3 1 2 3 4 5 6 7 2 Full Name ______________________________ ACCELERATION PRACTICE PROBLEMS Date ________ Period __________ Seat _____ Graph 1 Distance as a Function of Time (Speed Graph) 26 Legend 24 Bob : 22 Ted: 20 18 Distance (m) 16 5. Complete the following sentence: 14 Because Bob was traveling at a constant ____________, the shape of his graph line on the distance—time (speed) graph is a _________________ line. Ted’s motion however, was not one of constant speed, but of _________________. Because Ted was continuously increasing his speed, his graph line is the shape of a ___________. 12 10 8 6 4 2 0 0 1 2 3 4 5 6 7 8 9 Time (s) Graph 2 Velocity as a Function of Time (Acceleration Graph) Legend Speed (m/s) 8 7 Bob : 6 Ted: 5 4 3 2 1 0 0 1 2 3 4 5 6 Time (s) 3 7 8 9 6. On this velocity-time (acceleration) graph, how does the graph line Bob made compare to the graph line that Ted made? __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________