In the Figure below, we see a 200 gram block resting on the horizontal portion o
ID: 1590362 • Letter: I
Question
In the Figure below, we see a 200 gram block resting on the horizontal portion of a "track", whose left end is curved upwards. The horizontal portion of the track is frictionless, except for a 80.0 cm long "rough" portion, shown in the Figure, where the coefficient of kinetic friction is 0.400. The curved portion of the track is frictionless The block is held against a spring (which has a stiffness constant of 1,000 N/m), compressing the spring by 10.0 cm Then the block is released from rest. (NOTE: The block is not attached to the spring; it is just held against the end of the spring.) 80.0 cmExplanation / Answer
13) c. 4.37J.
Workdone by spring, Ws = 0.5*K*x^2
= 0.5*1000*0.1^2
= 5 J
Workdone by friction, Wf = -mue_k*m*g*d
= -0.4*0.2*9.8*0.8
= -0.6272 J
when it goes up it comes to stop.
so, net workdone = 0
Ws + Wf + Wg = 0
Wg = -(Ws + Wf)
= (5 - 0.6272)
= -4.37 J
14) e. 2.23m
Wg = -m*g*h
==> h = -Wg/(m*g)
= 4.37/(0.2*9.8)
= 2.23 m
15) c. +4.37J
delta_U = -Workdone by gravity