To determine the acceleration at $t = 1$ second from a plot describing motion along a straight line, we typically need to examine the type of plot provided. If it’s a position-time plot, acceleration can be calculated by finding the second derivative of the position with respect to time. If it's a velocity-time plot, acceleration can be obtained directly by calculating the slope at that specific point (since acceleration is the rate of change of velocity).

Could you please provide more details about the type of plot (position vs. time, velocity vs. time, or something else), or upload an image of the plot? This will allow me to assist you more accurately.

After providing the plot or more details, I can guide you further.