more physics?

1 ⤊

a coffee cup on the dashboard of a car slides forward on the dash when the driver decelerates from 40 km/h to 0 in 3.5 seconds or less, but not if he takes a longer time. What is the coefficient of static friction between the cup and the dashboard?

2006-12-13 06:31:02 · 2 answers · asked by The Answer 1 in Science & Mathematics ➔ Physics

2 answers

F=ma
f=uN
N=mg
N=-F

a=[(40/1000)3600]/3.5=41.1

u=ma/mg
u=a/g=41.1/9.81 =4.2
u=4.2

2006-12-13 06:41:10 · answer #1 · answered by Edward 7 · 0⤊ 0⤋

Why are you in a physics class if you don't want to do the work?

2006-12-13 14:39:29 · answer #2 · answered by Daniel H 5 · 1⤊ 0⤋