Answer:
1.66 kg
Explanation:
Given that a 0.83-kg block is hung from and stretches a spring that is attached to the ceiling.
From Hook's law
F = Ke
But F = mg
Substitute mg for force in the Hook's law
Mg = ke
0.83 × 9.8 = ke
Make K the subject of formula
8.134 = Ke
K = 8.134 /e
Given that a second block is attached to the first one, and the amount that the spring stretches from its unstretched length triples.
That is
(0.83 + M) × 9.8 = K (3e)
Substitutes K into the above equation
(0.83 + M) × 9.8 = 8.134 / e (3e)
The e will cancel out
(0.83 + M) × 9.8 = 24.402
0.83 + M = 24.402/9.8
0.83 + M = 2.49
M = 2.49 - 0.83
M = 1.66 kg
Therefore, the mass of the second block is 1.66kg
Answer:
One way to look at this is to consider the forces acting on any point in a string.
For a very small portion of string F = M a must still hold. As M approaches zero the small portion of string would have to approach infinite acceleration if the net force on that portion of string were not zero.
One generally considers the net force acting on the center of mass of an object not the individual forces acting on each infinitesimal mass composing
the object.
The answer for this is yes.