A hockey puck rebounds from a board as shown in Figure 16. Figure 16 looks like this. http://img174.imageshack.us/img174/2571/fig16vr6.png The puck is in contact with the board for 2.5ms. Determine the average acceleration of the puck over the interval. ------- So I know you have to use vector components. The answer says the avg. acceleration is 7.3x10^3m/s^2 [7.5 N of W] (degrees). How do I solve it? =/ I have made an attempt. I found that the vector components for v1x and v2x to add up to 43.57, and the components of v1y and v1x to add up to (-1.87). However, I'm not getting the correct average acceleration value in the end.