**Question on accelaration 2 (pls guide me,tq)** A 40-kg girl and a 8.4-kg sled are on the surface of a frozen lake, 15 m apart. By means of a rope the girl exerts a 5.2 N force on the sled pulling it toward her. a. What is the acceleration of the sled? b. What is the acceleration of the girl? c. How far from the girl’s initial position do they meet presuming the force remains constant and the no frictional forces act? *Here is my working,am i right?Pls guide me.Thank you.*
a.the acceleration of the sled = a,
F = m1 * a
a = (F/m1)
F = 5.2 N
a = (5.2/40)
= 0.13 m/s2
b.the acceleration of the girl = a1,
F = m2 * a1
a1= (F/m2) = (5.2/8.4)
= 0.62 m/s2
c.The distance covered by the sled when the girl pulls it is
S = ut + (1/2)at2
S = 15 m,u = 0 m/s and a = 0.13 m/s2
15 = 0 * t + (1/2) * 0.13 * t2
t2= (15/0.065) = (15000/65)
t = 15.2s
The distance from the girl's initial position when they meet is
S1 = ut + (1/2)a1t2
u = 0 m/s
S1 = 0 * 15.2 + (1/2) * 0.62 * (15.2)2
S1 = 71.6 m
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Last edited by jonbrutal; Jan 26th 2009 at 04:45 AM.
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