The same cricket ball changes its momentum by 10.5 kg.m/s while it stays in contact with the bat for 0.020 s. What average force does the bat exert on the ball?

1. Impulse is the product of the net force and the time interval over which that force acts. 2. The impulse on an object is also equal to the change in momentum of that object. 3. So the change in momentum of 10.5 kilogram metres per second is the impulse delivered by the bat. 4. Rearranging gives the average force as the impulse divided by the contact time. 5. That is 10.5 kilogram metres per second divided by 0.020 seconds, which equals 525 newtons. 6. The change in momentum points towards the bowler, so the average force points towards the bowler too. 7. The 0.21 newton answer traps anyone who multiplies by the contact time instead of dividing by it. 8. The 210 newton answer comes from dividing by 0.05 seconds rather than 0.020 seconds, and the 1050 newton answer comes from doubling the true impulse before dividing. _Source: Siyavula Physical Sciences Grade 12 (Everything Science, CC BY 4.0), Chapter 2: Momentum and impulse_