(1)A ball is moving in a straight line along the x-axis (units are in feet). it has an acceleration of 3t+1 feet
  per second squared. it's velocity at time t=0 is 16 feet per second and it initially starts at x=7
1)find the time at which the object turns around after heading left.
2)determine whether the object is speeding up, slowing down, or neither, at t=5secods
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