1 / 5

Momentum

Momentum. Definition: Momentum = mass x velocity. p = mv. (kg ·m/s). What has more momentum? a 25 kg artillery shell going 600 m/s, a 900 kg Honda Civic going 50 km/h. v HC = 50 km/h. = 13.9 m/s. p A = (25kg)(600m/s). = 15000 kg·m/s. p HC = (900kg)(13.9m/s).

herman-munoz
Download Presentation

Momentum

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 Definition:Momentum = mass x velocity p = mv (kg·m/s) What has more momentum? • a 25 kg artillery shell going 600 m/s, • a 900 kg Honda Civic going 50 km/h. vHC = 50 km/h = 13.9 m/s pA = (25kg)(600m/s) = 15000 kg·m/s pHC = (900kg)(13.9m/s) = 12500 kg·m/s The artillery shell has more momentum.

  2. Impulse Definition:Impulse = the change in momentum(caused by a force) Δp = mv - mvo Example: • A baseball of mass 600 g is thrown towards a batter at 30 m/s and hit back towards the pitcher at 50 m/s. Find the impulse. 30 m/s -50 m/s Δp = mv - mvo = (0.6)(-50) – (0.6)(30) = - 48kg·m/s The impulse applied to the baseball is 48kg·m/s towards the pitcher.

  3. Force & Impulse F = ma F = m (v – vo)Δt F = mv – mvoΔt F = ΔpΔt “Force = the rate of change of momentum” In the previous problem, the bat is in contact with the ball for 0.2 seconds. Find the average force. F = ΔpΔt = - 48 kg·m/s0.2s = - 240 kg·m/s2 = - 240 N 240 N of force towards the pitcher.

  4. Example: • Rambo fires his AK-48 machine gun. This gun fires 100 bullets per minute (each bullet = 175g). Find the average recoil force. The muzzle velocity is 950m/s. F = ΔpΔt = pf – poΔt Δt =60s po=0 pf= mv = 100 (0.175 x 950) = 16600 kg·m/s F=16600 - 0 60 =280 N Note: Δp = FΔt

  5. Homework

More Related