9. A position-time graph for a particle moving along the x axis is shown in Figure P2.9. (a) Find the average velocity in the time interval t = 1.5 s to t = 4.0 s. (b) Determine the instantaneous velocity at t = 2.0 s by measuring the slope of the tangent line shown in the graph. (c) At what value of t is the velocity zero?

Position, Velocity, and Acceleration 1. A position-time graph for a particle moving along the x axis is shown in the figure. (a) Find the average velocity in the time interval t = 1.50 s to t = 4s (b) Find the average velocity in the time interval t = 1.00 s to t = 6.00s (c) Determine the instantaneous velocity at t = 2.00 s by measuring the slope of the tangent line shown in the graph. (d) At what value of t is the velocity zero x (m) -t (s) 5 -12 -10 -8 -6 4 2- 0. 9 3 6

Traumatic brain injury such as concussion results when the head undergoes a very large acceleration. Generally, an acceleration less than 800 m/s2 lasting for any length of time will not cause injury, whereas an acceleration greater than 1000 m/s2 lasting for at least 1 ms will cause injury. Suppose a small child rolls off a bed that is 0.36 m above the floor. If the floor is hardwood, the child's head is brought to rest in approximately 2.2 mm. If the floor is carpeted, this stopping distance is increased to about 1.2 cm. Calculate the magnitude and duration of the deceleration in both cases, to determine the risk of injury. Assume that the child remains horizontal during the fall to the floor. Note that a more complicated fall could result in a head velocity greater or less than the speed you calculate. Hardwood floor magnitude  m/s2 duration  ms Carpeted floor magnitude  m/s2 duration  ms

A particle moves in one dimension, and its position as a function of time is given by x (2.0 m/s)t + (-3.6 m/s²)e². (a) What is the particle's average velocity from t 0.45 s to t = 0.55 s? (Indicate the direction with the sign of your answer.) m/s (b) What is the particle's average velocity from t = 0.49 s to t = 0.51 s? (Indicate the direction with the sign of your answer.) m/s MacBook Air 888 F1 F2 F3 F4 F5 F6 @ #3 $4 3 4 Q W E R T G