Velocity vs. Time 10 Velocity (m/s) 1 0 1 2 3 4 5 6 7 b ) Time (s) Displacement vs. Time 2.5 2 Displacement (m) 1,5 1 0 100 200 300 400 500 600 700 C ) Time (s) 15. An object's 1 dimensional motions are described by a series of sketched graphs, as seen below. Where t = time, a = acceleration, v = velocity, and x = position. All values in the graphs are positive, as indicated by the 0 at the origin. a a G D) A) E H) B t C) F) In which case(s) is the object in the process of definitely speeding up? In which case(s) is the object in the process of definitely slowing down? In which case(s) is the object definitely not in the process of changing its speed?Definitions 9. For each circumstance, below, describe a situation in which it can happen. Write "N/A" if it is not possible, and explain why. (a) velocity, v , is not constant and speed, v , is constant (not 0) (b) speed is not constant and velocity is constant (not 0) (c) displacement, A x , is constant (not 0) and acceleration, a , is constant (not 0) (d) acceleration, a , is not constant (not 0), acceleration, a , is constant (e) displacement, A s , is constant (not 0), and velocity, v , is not constant. 10. An object's motion at a moment in time nt in time is described by four cases below. (a) a=+2mls?i, v=+5mlsi, s=+3mi (b) a =-2mls'i, v=+5mlsi, s=+3mi (c) a=+2mls2i, v=-5mlsi, 5=-3mi (d) a=-2mlsi, v=-5mlsi, 3=-3mi where a = acceleration, v = velocity, and s = position. [Note: Each case should appear once in one of the slots. Despite what some students claim, for example, it is impossible for this object to speed up and to slow down at the same.] (a) In which case(s) is (are) the object in the process of speeding up? (b) In which case(s) is (are) the object in the process of slowing down?_ (c) In which case(s) is (are) the object not in the process of changing its speed? 11. Greg is driving a car to our right, sees the light is red, slams on his brakes, and skids toward the light (in a straight line). (a) While skidding, what is the direction of the car's velocity? (b) What is the direction of the car's acceleration, a ? 12. When are position and displacement interchangeable? 13. When is average speed the same as the magnitude of average velocity? Graph 14. Describe the motion necessary to create the displacement graphs. Displacement vs. Time 50 40 30 Displacement (m) 20 10 0 0 1 2 3 5 6 7 Time (s) a)Possible, if object . move in circular motion is. Chang, with tinct - speed 9. Constant, non-zero displacement AND velocity that is not constant? Possible 10. Constant, non-zero displacement AND non-zero speed? not Pess 11. Constant, non-zero displacement AND constant, non-zero velocity? Pos if object move in straight line 12. Constant, non-zero displacement AND constant, non-zero acceleration, a ? 13. constant, non-zero acceleration, a , AND velocity that is not constant? 14. Constant displacement AND velocity that is not constant? 15. Constant displacement AND constant acceleration, a ? Possible 16. acceleration, a , velocity, and displacement are all constant? not Pos 17. acceleration, a , that is not constant AND constant acceleration, a ? not 18. acceleration, a , that is not constant AND constant, non-zero velocity? PO 19. equal velocity with another object but in opposite directions