Problem 54 The vector position of a 3.50-g particle moving in the xy plane varie
ID: 1795270 • Letter: P
Question
Problem 54 The vector position of a 3.50-g particle moving in the xy plane varies in time according to r,-(31+ 3j): + 2jl2, where t is in seconds and T is in centimeters. At the same time, the vector position of a 5.50 g particle varies as= 3-2 it 2-6% At 1 = 2.50 s, determine (a) the vector position of the center of mass, (b) the lin- ear momentum of the system, (c) the velocity of the cen- ter of mass, (d) the acceleration of the center of mass, and (e) the net force exerted on the two-particle system. , CENGAGE 'Learning NotesExplanation / Answer
given m = 3.5 g
r1 = (3i + 3j)t + 2jt^2
r is in cm
M = 5.5g
r2 = 3i -2it^2 - 6jt
at t = 2.5 s
a. rcom = (mr1 + Mr2)/(m + M)
r1 = 7.5i + 20j cm
r2 = -9.5i - 15j cm
hence
rcom = -2.888i - 1.388 j cm
b. v1 = 3i + 3j + 4jt
v2 = -4it - 6j
at t = 2.5 s
v1 = 3i + 13j cm/s
v2 = -10i - 6j cm/s
hence
linear momentum = mv1 + Mv2 = -44.5i + 12.5j g cm/s
c. Vcom = (mv1 + Mv2)/(m + M) = -4.9444i + 1.3888j cm/s
d. a1 = 4j
a2 = -4i
hence
acom = (ma1 + Ma2)/(m + M) = -2.444i + 1.5556 j cm/s/s