posted by Gloria .
If motor M exerts a force of
F=(10t2+100)N on the cable, where t is in seconds, determine the velocity of the
25kg crate when
t=4s . The coefficients of static and kinetic friction between the crate and the plane are
μs=0.3 and 0.25
μk=0.25 . The crate is initially at rest.
F = 10*4^2 + 100 = 260 N.
Wc = m*g = 25 * 9.8 = 245 N. = Wt. of crate.
Fk = uk*mg = 0.25 * 245 = 61.25 N. =
Force of kinetic friction.
a = Fn/m = (F-Fk)/m = (260-61.25)/25 =
V = a * t = 7.95 * 4 = 31.8 m/s.