Please answer to parts with ???? , good lcuk A box contains machinery that can r
ID: 3163927 • Letter: P
Question
Please answer to parts with ???? , good lcuk
A box contains machinery that can rotate. The total mass of the box plus the machinery is m = 5 kg. A string wound around the machinery comes out through a small hole in the top of the box. Initially the box sits on the ground, and the machinery inside is not rotating (left side of the figure below).
Then you pull upward on the string with a force of constant magnitude F = 94 N. At an instant when you have pulled d = 0.47 m of string out of the box (indicated on the right side of the figure), the box has risen a distance of h = 0.18 m, and the machinery inside is rotating.
POINT PARTICLE SYSTEM
What is the y component of the displacement of the point particle system during this process?
y = 0.18 m
What is the y component of the net force acting on the point particle system during this process?
Fnet,y = 45 N
What is the distance through which the net force acts on the point particle system?
0.18 m
How much work is done on the point particle system during this process?
W = 8.1 J
EXTENDED SYSTEM
The extended system consists of the box, the machinery inside the box, and the string.
What is the translational kinetic energy of the extended system, at the instant shown in the right diagram?
Ktrans = ????? J
What is the distance through which the gravitational force acts on the extended system?
?????? m
How much work is done on the system by the gravitational force?
Wgrav = ????? J
What is the distance through which your hand moves?
????? m
How much work do you do on the extended system?
Whand = ?????? J
At the instant shown in the right diagram, what is the total kinetic energy of the extended system?
Ktotal = ?????? J
What is the rotational kinetic energy of the machinery inside the box?
Krot,f = ??????? J
Explanation / Answer
According to the given problem,
EXTENDED SYSTEM :
A) K trans = Fnet *h = 45*0.18 = 8.1 J
B) The distance through which the gravitational force acts is, h = 0.18m
C) W grav = - mgh = - 49*0.18 = -8.82J
D) Total Distance travelled = d + h = 0.18 + 0.47 = 0.65 m
E) W hand = F hand *(d+h) = 94 *0.65 = 61.1 J
F) K total = W grav + W hand = 52.28 J
G) K rot,f = K total - K trans = 44.18J