Inelastic collision

[Maxine450]

---

Members do not see this ad.

Here's a question that's been bothering me. In the Berkeley Review chapter on momentum, about the two skaters, say that you didn't know their mass. If one skater collides into another in an inelastic collision, which one feels the greater force?

The moving skater, the stationary skater, they both feel the same force, or more information is needed.

 

[milski]

Same force. You don't even need to think about momentums, these are Newton's 3rd law forces.

 

[SaintJude]

Yup. You' may be wondering, "what variables are different?" Acceleration and Impulse. The skater with the lesser mass would experience a greater acceleration.

Also when two vehicles of unequal mass collide head-on at the same speed, the vehicle experiencing the greater impulse (the vehicle that will undergo the greatest change in velocity), will be vehicle of lesser mass. So when a huge truck and a mini Volkswagen collide head-on at the same speed, Volkswagen will experience the greater impulse.

 

[milski]

Yup. You' may be wondering, "what variables are different?" Acceleration and Impulse. The skater with the lesser mass would experience a greater acceleration.

Also when two vehicles of unequal mass collide head-on at the same speed, the vehicle experiencing the greater impulse (the vehicle that will undergo the greatest change in velocity), will be vehicle of lesser mass. So when a huge truck and a mini Volkswagen collide head-on at the same speed, Volkswagen will experience the greater impulse.

I read that too quick. The impulses for both objects are the same too. Remember that the impulse is F*t - both of these are the same for each object. The smaller car has a smaller mass which means that the same impulse (same change of momentum) will result in a larger change of speed.

Btw, there is no point in saying that they colide 'at the same speed' - in any collision you can find a reference frame in which the speed is the same for the two objects.

 

[SaintJude]

Oh, yeah sorry! Impulse will be the same, but the change in velocity will still be different between the two objects! Impulse also equals mass * (delta velocity) = F * t. Which is the same point as acceleration being different, so I guess I made the same point twice.
Thanks for covering my sloppiness! Lethal for the mcat...