Explanation:
The given data is as follows.
Spring constant (k) = 78 N/m, 
Mass of block (m) = 0.50 kg
According to the formula of energy conservation,
mgh sin
h =
= 
= 0.64 m
Thus, we can conclude that the distance traveled by the block is 0.64 m.
<h3>Answer;</h3>
<u>It would make the lens stronger. </u>
<h3>Explanation;</h3>
- The focal length is the distance between the optical center or the center of the lens to the focal point of a convex or concave lens.
- The power of the convex lens is lens ability to undertake refraction or bend light. It is given as the reciprocal of focal length.
- Power of the lens = 1/ f; therefore the smaller the focal length the higher the power and the larger the focal length the lower the power.
- Thus; decreasing the focal length of a convex lens makes the lens stronger.
The velocity of the wave on the string is given by

Solving the above equation,

The frequency of the wave
and wave length is 
The velocity is 
Substituting numerical values,

The length of the string is 