When a 3.40-kg object is hung vertically on a certain light spring that obeys Hooke's law, the spring stretches 2.60 cm. (a) If the 3.40-kg object is removed, how far will the spring stretch if a 1.50-kg block is hung on it? 1.15 cm (b) How much work must an external agent do to stretch the same spring 4.00 cm from its unstretched position? 1.0256 Correct: Your answer is correct. J

Respuesta :

Answer:

a).1.147cm

b).1.0256 J

Explanation:

Using law of force and applications Law Hooke

[tex]F=k*d[/tex]

[tex]d=\frac{F}{k}[/tex]

But first have to know force and constant in initial conditions

[tex]F=3.4kg*9.8\frac{m}{s^{2}} \\F=33.32N\\k=\frac{F}{d}\\ d=2.6cm\frac{1m}{100cm}=0.026m=26x10^{-3}m[/tex]

[tex]k=\frac{33.23N}{26x10^{-3}}=1281.53 \frac{N}{m}[/tex]

a).

[tex]d=\frac{F}{k}[/tex]

[tex]d=\frac{1.5kg*9.8\frac{m}{s^{2}}}{1281.53 \frac{N}{m}}=\frac{14.7N}{1281.53 \frac{N}{m}}\\  d=0.0147m=11.47x10^{-3}m[/tex]

[tex]d=11.47x10^{-3}m*\frac{100cm}{1m} \\d=1.147cm[/tex]

b).

Wokr is the force done so using the equation

[tex]d=4cm*\frac{1m}{100cm}=0.04m[/tex]

[tex]Ew=\frac{1}{2}*k*d^{2}\\Ew=\frac{1}{2}*1281.53N*(0.04m)^{2}  \\Ew=1.025N*m^{2} \\Ew=1.025 J[/tex]