Work/KE
W = Fd = ∆KE
F = average Force W neg : decrease KE W + : increase KE
Neglecting gravity, estimate the average force of friction if the
W = Fd = ∆KE 95 km/hr [1000m/1km][1 hr/3600 sec]
= 26.39 m/s = V
.9[26.39 m/s] = 23.75 m/s = V
∆KE = 1/2m[V Fd = ∆KE F = ∆KE/d
F = -1.1 N
p. 162) 20
Ex) baseball (m = 140 g) travelling 32 m/s caught by a glove and moves glove back 25 cm. Average F of ball on glove?
Work of glove on ball = ΔKE
W
Fd = 1/2m[V
F[.25m] = 1/2[.14kg][0 - (32m/s)
F
F Average F of ball on glove?
F
ŠTony Mangiacapre., - All Rights Reserved [Home] Established 1995 Use any material on this site (w/ attribution) |
|||