s your project with a spring in its step! [35 pts] A very large force 400 N is s
ID: 1791163 • Letter: S
Question
s your project with a spring in its step! [35 pts] A very large force 400 N is supplied n, it was observed to an object at rest with a mass m = 1 kg for a very short time 0.01 s . Later o that the object passed a flat part with a distance of,, 1m, over a straight hill of height h = 5 cm and angle 30°, and then finally onto a flat plateau. The coefficients of static and kinetic friction are = 0.15 and ,-0.10 respectively. Where would a spring (k = 20 N/m) need to be placed to ensure that the object stopped at roughly the same place it started? . Use Energy and Work Concepts. NOTE: The spring is attached to the ground and does not move.Explanation / Answer
Applying work energy theorem,
Work done by force + work done by gravity + work doneby friction +work done by spring = change in KE
Work done by gravity = 0
Work done by force :
a = F / m = 400 m/s^2 and d = a t^2 /2 = 0.02 m
W = F.d = 8 J
Work done by spring = 0
Work done by friction:
on flat surafce, N = m g
f1 = uk N = 0.981 N
W1 = - 2(0.981 x (1 + d))
W1 = - (1.962(1 + d))
on incline, N = m g cos30
f = uk m g cos30
W2 = - 2 ( f h / sin30) = - 1.70 J
Work done by friction = - 3.40 - 1.962 d
putting in ,
8 - 3.40 - 1.962 d = 0 - 0
d = 2.34 m
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