Question

To increase the change in momentum of an object, it makes sense to apply the greatest force possible for as long as possible. Which scenario shows this concept?


When a baseball player is trying for a home run, he or she swings as hard as possible and tries to follow through with their swing to keep the ball on the bat for as long as possible

A car accelerates from 0m/hr to 60m/hr in 20 seconds

A boxer jabs someone quickly

A diver jumps into the water "jackknife" style

Answer 1

The first scenario — the baseball player swinging as hard as possible and following through to keep the ball on the bat longer.

Reason: change in momentum (impulse) is Δp = ∫F dt ≈ F_avg · Δt. Swinging hard increases the force and following-through increases the contact time, so the impulse (and therefore the ball’s change in momentum) is maximized.

Why the others don’t fit as well:
- Car accelerating 0→60 over 20 s: the force may be relatively small but applied for a long time — not an example of trying to maximize both force and contact time in the way described.
- Boxer jabs quickly: large force but very short contact time → smaller impulse than a longer contact would give.
- Diver jackknife: that maneuver minimizes water resistance and abrupt deceleration, so it’s not used to increase change in momentum.