Question

A block whose mass is 650 gm is fastened to aspring constant K equals 65 N/m whose other end is fixed. The block is pulled a distance x = 11 cm from its equilibrium position at x = 0 on a smooth surface, and released from rest at t = 0. The maximum speed ‘S’ of the oscillating block is

(a) 11 cm /sec

(b) 11 m/sec

(c) 11 mm/sec

(d) 1.1 m/sec

The question was posed to me by my college professor while I was bunking the class.

This interesting question is from Coefficient of Friction in portion Friction of Machine Kinematics

Answer 1

The correct answer is (d) 1.1 m/sec

Easiest explanation: Maximum speed of the spring will be at x = 0, when total spring energy will be converted into kinematic energy of mass.

1/2 kx^2 = 1/2 mv^2

1/2 x 65 x(0.11)^2 = 1/2 x (0.650)V^2

V = 1.1 m/sec.