Initial velocity=u=15m/s
Final velocity=v=10m/s
Time=0.08s
[tex]\\ \sf\longmapsto Acceleration=\dfrac{v-u}{t}[/tex]
[tex]\\ \sf\longmapsto Acceleration=\dfrac{10-15}{0.08}[/tex]
[tex]\\ \sf\longmapsto Acceleration=\dfrac{-5}{0.08}[/tex]
[tex]\\ \sf\longmapsto Acceleration=-62.5m/s^2[/tex]