question_answer

A 250 g ball moving at 20 m/s is stopped by a player in 0.01 second. What impulse did the ball exert on to player's hand?

Answer:

\[m=250\,\,g=0.25\,\,kg\] \[v=20m/s\] \[t=0.01s\] impulse \[(I)=?\]                 \[I=F\times t\]                  ………. (1) But         \[F=ma\]                             ………. (2) Now \[a=\frac{V}{t}=\frac{20}{0.01a}m/{{s}^{2}}=2000m/{{s}^{2}}\] Substituting the above value in (2), we get \[F=0.25\times 2000=500N\] Substituting the above value in (1), we get \[\therefore I=F\times t=500N\times 0.01s=5\,\,Ns\]