In the figure below, we must apply a force of magnitude 63 N to hold the block s
ID: 1544386 • Letter: I
Question
In the figure below, we must apply a force of magnitude 63 N to hold the block stationary at x = 2.0 cm. From that position we then slowly move the block so that our force does +3.0 J of work on the spring-block system; the block is then again stationary.
What is the spring constant of the spring?
N/m
When you move the block from its initial position to its final position, does the mechanical energy of the block-spring system increase, decrease, or remain the same?
Increase Remain the same Decrease
What is the block's final position x? (There are two answers.)
cm (negative value)
cm (positive value)
Explanation / Answer
F = k*x
k = spring constant
x = distance moved from origin
K = F/x = 63/0.02 = 3150 N/m
----------------
increases
--------------
work done by force W = +3 J
work done is stored as elastic potential energy in the spring block system
W = (1/2)*k*x^2
3 = (1/2)*3150*x^2
x = 0.044 m = 4.4 cm or - 4.4 cm
final position = -2 + 4.4 = +2.4 cm <<<<<+++++++ANSWER
and
final position = -2 - 4.4 = -6.6 cm <<<<+++++++ANSWER