Answer:
can you post the full question plz
Explanation:
Answer: 
Explanation:
We have the following equation:

We have to find
this means we have to isolate it:


Answer:


Explanation:
Wave 1, 
Wave 2, 
Wave 3, 
Wave 4, 
The general equation of travelling wave is given by :

The value of
will remain the same if we take phase difference into account.
For first wave,



For second wave,



For the third wave,



For the fourth wave,



It is clear from above calculations that waves 1 and 3 have same time period. Also, wave 2 and 4 have same time period. Hence, this is the required solution.
The spring should have a greater displacement .
Greater spring constant = the more difficult it is to stretch a spring , due to stiffness.
To solve this problem we will apply the given concept for torque which explains the relationship between the force applied and the distance to a given point. Mathematically this relationship is given as

Where,
Torque
F = Force
d = Distance
Our values are given as,

Therefore replacing we have that the force is

F = 12.72N
Therefore the least amount of force that you must exert is 12.72N