Question

A block is attached to one end of a spring so that it can bounce back and forth on a horizontal frictionless surface. The block is pulled a distance of 0.150 m away from equilibrium and released. When the block is 9.00 cm away from equilibrium, it is traveling with a speed of 0.800 m/s. If the spring constant of the spring is 60.0 N/m, what is the mass of the block?

Answer 1

here,

the amplitude of motion , A = 0.15 m

when x1 = 9 cm = 0.09 m , the speed v1 = 0.8 m/s

the spring constant , K = 60 N/m

let the mass of block be m

using conservation of energy

0.5 * K * A^2 = 0.5 * K * x1^2 + 0.5 * m * v1^2

60 * 0.15^2 = 60 * 0.09^2 + m * 0.8^2

solving for m

m = 1.35 kg

the mass of block is 1.35 kg