This question was part of a 2 part question. I figured out the first part of it. I can't get the 2nd half of it. The formula for a lightweight object, such as a styrofoam ball is v=v_t(1-e^kt) where V_t=5.70 m/s is the terminal speed, k=1.72s^-1 is the drag coefficient of the styrofoam ball, t is the clock reading, in seconds, and e is 2.7183.., the base of the natural logarithms. What is the magnitude of the acclelration of the ball at t=0.5s? What is the average acceleration of the ball during the time intercal from t=0 to t=0.5 s? I figured out the magnitude of the acceleration of the ball at t=0.5 is 4.15 m/s^2. For the second part of the question I derived the formula up top making it k*e^(-k*t)*v_t. I plugged in the values and used 5.0 for t and did it again using 0 for t. I then subtracted the 2 values I got for t and ended up with 5.654. I can't figure out what I did wrong.