1 / 14

Momentum and Impulse

Momentum and Impulse. Inertia In Motion. Which is harder to stop? A car moving at 25 m/s A bicycle moving at 25 m/s Why is it harder to stop?. Momentum. Momentum can be defined as the measurement of how difficult it is to change the motion of an object. Mathematically:

roana
Download Presentation

Momentum and Impulse

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Momentum and Impulse

  2. Inertia In Motion • Which is harder to stop? • A car moving at 25 m/s • A bicycle moving at 25 m/s • Why is it harder to stop?

  3. Momentum • Momentum can be defined as the measurement of how difficult it is to change the motion of an object. • Mathematically: • Momentum = (mass) * (velocity)

  4. Which has more momentum? A sumo wrestler running towards you? A ballerina running towards you at the same speed?

  5. Calculating momentum • What is the momentum of a 10 kg bowling ball rolling at 4 m/s? • Momentum = (mass) * (velocity) • Momentum = (10 kg) * (4 m/s) • Momentum = 40 kg*m/s

  6. Units for momentum • The units for momentum are (kg*m/s). • The units are not abbreviated into any other form (unlike Newtons)

  7. Changing momentum • If the momentum of an object changes, then either the mass, velocity or both has changed. • Usually, the mass of an object remains the same, so it’s the velocity that is changing. • What is the quantity that measures the change in velocity?

  8. Change in momentum continued • What causes an acceleration? • Therefore, the greater the force on an object, the greater the change in momentum. • Now for a little bit of math…

  9. Newton’s 2nd Law Change in momentum Force = mass acceleration * * Time Force*Time is also known as “Impulse”

  10. Impulse • A force can be used to change an object’s motion. • Impulse is how quickly or slowly that change in momentum occurs. • The amount of time it takes to change the object’s motion is called impact.

  11. Increasing momentum • Force*Time = change in momentum • To get the greatest change in momentum, you need a greater force acting for a longer period of impact time. • Example: hitting a golf ball - http://www.youtube.com/watch?v=2Y57pw_iWlk • Example: Hitting a baseball with a metal bat.

  12. Decreasing momentum • This is the situation where you are trying to STOP something from moving. (change the momentum to zero) • Force * Time = change in momentum • Suppose an object has very high momentum • How can we decrease the force the object will feel when we try to stop the object?

  13. Decreasing momentum examples • Bungee jumping • Air bags • Boxing glove • Baseball glove • Pole vault mats • Catching a lacrosse ball

  14. Calculating Impulse • An 8kg bowling ball traveling at 4 m/s rolls into a pillow and stops in 2 seconds. Calculate the force the pillow exerts on the bowling ball. • Force*Time = change in momentum • Force*Time = mass*velocity • Force*(2 seconds) = (8kg)*(4m/s) • Force*(2 seconds) = 32 (kg*m/s) • Force = 16 Newtons

More Related