Direction Change Force Calculator

Festival context —In the war scene, a performer must change from running forward to reversing direction. Set the mass, initial speed, final speed, and beat count time. Calculate the force their legs must generate.

S9FE-IIIb-24Grade 9 · Quarter 3Relate Impulse to Change in Momentum

Direction Change Force Calculator

Interactive Simulator

"In the war scene, a performer must change from running forward to reversing direction. Set the mass, initial speed, final speed, and beat count time. Calculate the force their legs must generate."

War Scene · Direction Change

Reversing doubles the momentum change — watch the force grow.

Speed1×

Adjust Variables

Performer mass (kg)55 kg

40100

Initial speed (m/s)4 m/s

Final speed (m/s)-4 m/s

-88

Time allowed (s)0.5 s

0.22

Physics ReadoutsLIVE

Change in Momentum (Δp)-440.0 kg·m/s

Required Force880.0 N

deltaP = mass × (vf - vi); force = deltaP / time

Community Hub — Cultural Discussion

Reflect & Connect

The choreographer gives performers 2 beats vs. 4 beats to complete the same stop. Which requires more muscular force? As the developer of the reenactment, design a physically safer yet equally dramatic stopping sequence — what beat count and movement style would you recommend?

Discuss with your class or write your response in your science journal.

Performance Task

Catch a Ball Two Ways: Short vs. Long Impact Time

1Do

Have a partner gently toss a ball to you from the same height several times. Catch it first with stiff hands held rigidly in place. Then catch it by letting your hands 'give' — drawing them back toward your body as you catch, stretching the catch out over a longer moment.

2Measure

For each catch, rate the sting or force you feel in your hands from 1 to 5, and note roughly how long the catch lasted (a sharp snap vs. a drawn-out give). The incoming momentum is the same every time, since it is the same ball from the same height.

3Reflect

The 'giving' catch stretched the contact time, so the force dropped — even though the change in momentum was identical: J = F·Δt = Δp, competency S9FE-IIIb-24. This is the same physics as bending the knees on landing, or a car airbag. In the Cry of Jelicuon war scene, why does a performer told to 'fall slowly' over more beats feel less force than one who stops in a single beat?

Record your measurements and reflections in your science journal.

Module Overview

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Check Your Understanding: Momentum & Impulse