1 / 21

Momentum, Impulse, Work, Power

Momentum, Impulse, Work, Power. Harmandip Singh, Nasif Mahmud, Mohammed Yeashin, and Ajla Dupljak. What is Momentum ?. Momentum  – a measurement of the tendency of an object to stay in motion. SI Unit: [kg-m/s] Formula: momentum = (mass)(velocity) or p = mv. Momentum continued.

anise
Download Presentation

Momentum, Impulse, Work, Power

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, Impulse, Work, Power Harmandip Singh, Nasif Mahmud, Mohammed Yeashin, and Ajla Dupljak

  2. What is Momentum? Momentum – a measurement of the tendency of an object to stay in motion. SI Unit: [kg-m/s] Formula: momentum = (mass)(velocity) or p = mv

  3. Momentum continued - The momentum of a body is proportional to both its mass and velocity. If either one increases the momentum will also increase. - Momentum is a vector quantity whose direction is the same as the object's velocity.

  4. Practice Problem 1 1. If the mass of an object is 5kg, and the velocity is 7m/s, what is the momentum?

  5. Answer Formula first : p = mv p = (5kg)(7 m/s) 35 kg-m/s

  6. Problem # 2 2. What is the value of the momentum of a 10 kg ball running down a bowling alley at a speed of 5 m/s?

  7. Answer Formula first: p = mv p = (10 kg)(5 m/s)  50 kg-m/s

  8. Impulse Impulse- the product of the net force acting on an object and the time during which the force acts. The symbol for impulse is J. SI Unit: [kg-m/s] or [Ns] (Equivalent to momentum)The unit for impulse and the unit for momentum are equivalent. The Impulse is also the change in momentum for an object in motion. 

  9. Calculating Impulse •J= F net(T) = ΔP •(Force)(Time) = Impulse [kg * m/s2] •Δp= mΔv –Δp= m(v’-v) –Δp= mv’-mv –Δp= p’-p

  10. Practice Problem 3 3. A gust of wind exerts a 300. N net force on a 1000.-kg sailboat for 15 s. What is the change in the momentum and velocity of the boat?

  11. Answer Formulas first : J =Ft, p=mv,J= Δp J= (300.N)(15 s)= 4500  J= Δp= 4500kg-m/s p=mv v=p/m= (4500kg-m/s)/(1000.kg)= 4.5m/s

  12. Demonstration http://www.youtube.com/watch?v=NBaFIiBGjpI HW: AMSCO pg. 36-37  #153, 162, 170

  13. Work Work: In physics, work is done whenever a force acts on an object in the direction of the objects motion. If an object is not in motion no work is being done. Si Unit: J (Joule)1J = 1newton · meter = 1N · m- Work is the product of the magnitude of the applied force F and the objects displacement d in the direction of the force.-When calculating force only the force parallel to the objects motion can be used.-Work is a scalar quantity. If an object is not moving no work is being done.

  14. Practicing with Work and Power 1. How much work is done on a downhill skier by an average braking force of 9.8 × 102 Newtons to stop her in a distance of 10. meters?

  15. Solutions    1. Formula first: W=Fd     W= 9.8 × 102 N·10.m W=  9.8 ×103J

  16. 2. What is the work required to raise a 10. - kilogram box from the surface of the earth to a height of 5.0 meters?

  17. 2. Formulas first: w=mg, W=Fd     w= 10.kg × 9.8 m/s2     w= 98. N     W=Fd     W= 98.N ×5.0m     W= 490J

  18. Power Power is the amount of work done per unit time. Like work, it is a scalar quantity. The symbol for power is P. Power = (work/time) • P=W/t  • Since W=Fd, we can write: P= (Fd/t). • Since v= d/t we can write: P= (Fd/t)=Fv. • Thus, power can also be expressed as the product of the applied force and the velocity of the object • SI Unit = Watts --> J/Sec 

  19. 3. If energy is supplied at the rate of 10 watts, how much work is done during 2 seconds?

  20. 3. Formula first: P=W/t     Pt=W     10watts × 2s= W 20J=W

  21. Work and Power Demonstration     HW: AMSCO pg. 59-60  #1, 9, 17

More Related