Answer:
117.28 N/m
Explanation:
step one:
given
Period T= 0.367s
mass m= 0.4kg
Required
the spring constant k
Step two:
The expression for the period, mass and spring constant relation is
T=2π√m/k
making k subject of the formula

square both sides





Answer:
Its period if its length is increased by a factor of four is 5 s.
Explanation:
The period of a simple pendulum is given by;

Given;
initial period, T₁ = 2.5
initial length, = L₁
new length, L₂ = 4L₁
the new period, T₂ = ?

Therefore, its period if its length is increased by a factor of four is 5 s.
Answer:
The solutions is in the attached file
Explanation:
Check the following attached file
a) E=Nt=100*(4*3600)=1440000 J
b) E=1200*(5*60)=360000 J
c) Q=E*(100-1.8)/100=1414080 J