problem05_p107

University Physics with Modern Physics with Mastering Physics (11th Edition)

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
5.107: a) The forces on the car are the air drag force 2 D Dv f = and the rolling friction force . r mg μ Take the velocity to be in the x + -direction. The forces are opposite in direction to the velocity. x x ma F = gives ma mg Dv = - - r 2 μ We can write this equation twice, once with s m 32 = v and 2 s m 42 . 0 - = a and once with s m 24 = v and . m/s 30 . 0 2 - = a Solving these two simultaneous equations in the unknowns D and r gives 015 . 0 r = and . m s N 36 . 0 2 2 = D b) β mg n cos = and the component of gravity parallel to the incline is , sin
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mg where . 2 . 2 = For constant speed, . 2.2 cos 2.2 sin 2 r =-- Dv mg mg Solving for v gives . s m 29 = v c) For angle cos sin , 2 r =--Dv mg mg and D mg v ) cos (sin r-= The terminal speed for a falling object is derived from , 2 t =-mg Dv so . t D mg v = v v cos sin r t-= And since v v cos ) 015 . ( sin , 015 . t r-= =...
View Full Document

Ask a homework question - tutors are online