Free response · Unit 8 Beta

A particle with velocity 4cos(0.9t) - 0.2t

Particle motion · Part A: graphing calculator allowed · 9 points

The question

Name: ______________________   Date: ____________   A particle with velocity 4cos(0.9t) - 0.2t (9 points)

Table

A particle moving along the x-axis

The velocity of a particle, in meters per second, for 0 ≤ t ≤ 6 seconds, and its position at t = 0
QuantityValue
v(t)v(t)4cos⁡(0.9t)−0.2t4\cos(0.9t) - 0.2t meters per second, 0≤t≤60 \le t \le 6
x(0)x(0)3 meters
  1. (a) Is the speed of the particle increasing or decreasing at time t=2t = 2? Give a reason for your answer. [2 points]

  2. (b) Find all times tt in 0<t<60 < t < 6 at which the particle changes direction. Justify your answer. [2 points]

  3. (c) Find the position of the particle at time t=6t = 6. [2 points]

  4. (d) Find the total distance traveled by the particle over 0≤t≤60 \le t \le 6. Find the average velocity of the particle over the same interval. Indicate units of measure. [3 points]