Answer:
μ =tanθ
Explanation:=
The ratio of the force of static friction and the normal reaction is equal to tanθ. F=mgsinθ. R = mgcosθ.
μ=tanθ
Answer:

Explanation:
We have given initial length of the steel guitar l = 1 m
Cross sectional area 
Young's modulus 
Force F = 1500 N
So stress 
We know that young's modulus 
So 

Now strain 


Answer:
Pebble A has 1/3 the acceleration as pebble B.
Explanation:
F = m×a
mass of a = 3 × mass of b (m_a = 3 × m_b)
Same starting force, F
m_a = mass of a
m_b = mass of b
a_a = acceleration of a
a_b = acceleration of b
F = m_a × a_a = m_b × a_b
3 × m_b × a_a = m_b × a_b
3 × a_a = a_b
OR
a_a = a_b / 3
Answer:
Stretch can be obtained using the Elastic potential energy formula.
The expression to find the stretch (x) is 
Explanation:
Given:
Elastic potential energy (EPE) of the spring mass system and the spring constant (k) are given.
To find: Elongation in the spring (x).
We can find the elongation or stretch of the spring using the formula for Elastic Potential Energy (EPE).
The formula to find EPE is given as:

Rewriting the above expression in terms of 'x', we get:

Example:
If EPE = 100 J and spring constant, k = 2 N/m.
Elongation or stretch is given as:

Therefore, the stretch in the spring is 10 m.
So, stretch in the spring can be calculated using the formula for Elastic Potential Energy.