Answer:
(a) 294 N/m
(b) 0.027 m or 2.7 cm
Explanation:
(a) From Hook's law,
F = ke......................... Equation 1.
make k the subject of the equation
k = F/e..................... Equation 2
Where F = force applied on the spring, k = spring constant, e = extension.
From the question, the force applied to the spring is the weight of the mass.
F = mg = 0.75(9.8) = 7.35 N
Also, e = 2.5 cm = 0.025 m
Substitute these values into equation 2
k = 7.35/0.025
k = 294 N/m.
(b) If a mass of 800 g is suspended,
F = ke
e = F/k................... Equation 3
F = mg = 0.8(9.8) = 7.84 N,
k = 294 N/m.
Substitute these values into equation 3
e = 7.84/294
e = 0.027 m
e = 2.7 cm
