1 / 9

Force, time, mass, and  velocity Contents: New concept Example Whiteboards: 1 , 2 , 3 , 4

Force, time, mass, and  velocity Contents: New concept Example Whiteboards: 1 , 2 , 3 , 4. Force, time, mass, and  velocity. So far we have: p = mv, so  p = m v And Impulse =  p = F  t Impulse = F  t = m  v F = Force (N)  t = Elapsed time (s) m = Mass (kg)

santosbrown
Download Presentation

Force, time, mass, and  velocity Contents: New concept Example Whiteboards: 1 , 2 , 3 , 4

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. Force, time, mass, and velocity • Contents: • New concept • Example • Whiteboards: 1,2,3,4

  2. Force, time, mass, and velocity • So far we have: p = mv, • so p = mv • And Impulse = p = Ft • Impulse = F t = mv • F = Force (N) • t = Elapsed time (s) • m = Mass (kg) • v = Change in velocity (m/s)

  3. Example: A car going 34 m/s hits a .0025 kg bug. The collision lasts .020 seconds. What force does the windshield exert on the bug? • F t = mv • (F )(.02 s) = (.0025 kg)(34 m/s) • F = (.0025 kg)(34 m/s)/(.02 s) • F = 4.25 N (units?)

  4. Whiteboards Ft = mv 1 | 2 | 3 | 4

  5. What force for 10. seconds makes a 2.0 kg rocket speed up to 75 m/s from rest? 15 N (m)(v) = (F )( t) (2.0 kg)(75 m/s) = (F )(10 s) F = (2.0 kg)(75 m/s)/(10 s) = 15 N

  6. A baseball bat exerts a force of 200. N on a .50 kg ball for .10 seconds. What is the ball’s change in velocity? 40. m/s (m)(v) = (F )( t) (.50 kg)(v) = (200. N )(.10 s) v = (200. N )(.10 s)/(.50 kg) = 40. m/s

  7. Jolene exerts a 50. N force for 3.00 seconds on a stage set. It speeds up from rest to .25 m/s. What is the mass of the set? 6.0x102 kg (m)(v) = (F )( t) (m)(.25 m/s) = (50. N )(3.0 s) m = (50. N )(3.0 s)/(.25 m/s) = 600 kg = 6.0 x102 kg

  8. For what time must a 517 kg spaceship fire its retro rockets to slow it from 576 m/s to 312 m/s. The rockets generate 35,000 N of thrust. 3.9 seconds v = 576 m/s - 312 m/s = 264 m/s (517 kg)(264 m/s) = (35,000 N )( t)  t = (517 kg)(264 m/s)/(35,000 N ) = 3.9 seconds

  9. One last thing: • If we re-arrange things in • m v = F  t • t t • Now • v = acceleration, so • t • Which gives us • F = m v = ma = p • t t

More Related