🎬Flipping Physics: Impulse

What's with the scary music and everyone freaking out??

• That's going to hurt.

• No idea, man; I jump off of things with my knees locked all the time and nothing bad's ever happened to me. 🩼🤕

Sorry, that was how many Newtons, which is how many pounds? (Select both)

• 988 N

• 220 lbs

• like, so many Newtons

• 220 N

• 988 lbs

Organize these options into the right categories:

What changes when he DOESN'T bend his knees?

Groups:

(a) Changes

,

(b) Does NOT Change

• mass

• time of impact

• final velocity

• fall height

• initial velocity

What property is symbolized by the following variables:

J, I, Δp

Which of the equations below ARE Impulse Equations?

Select all that apply.

...and be careful.

Do the units check out?

If we are studying the effects of changing the time of impact in this equation, why does the Impulse remain the same?

• It has to, because the initial and final conditions of the collision haven't changed.

  (m, v_f, and v_i haven't changed)

• It doesn't necessarily have to, but in this specific case, it does.

• Because we know it hurts more when we land with straight knees, we know the force will change, not the impulse.

ESTIMATING: The original time of impact was around 0.30 s.

The new time of impact is around 0.03 s.

By what factor has the time decreased?

• 10 x faster

• 100 x faster

• 10 times slower (0.10)

• 100 times slower (0.01)

Ok, so if the Impulse has to remain the same, and the time reduced (roughly) by a factor of 10, by what factor (roughly) will the force increase AND what (roughly) will that final force of impact be?

Recall: original force of impact was 988 N.

• Increase by a factor of 10

• Decrease by a factor of 10

• 9880 N

• 98.8 N

Why is our estimation generally correct?

• We rounded time UP a little, making it a "slower" time, so it makes sense the force was actually a little larger than our estimates.

• We rounded time UP a little, making it a "faster" time, so it makes sense the force was actually a little larger than our estimates.

• It isn't! We were way off. 9880 vs 11066? that's over 1200 N off!