Question

1. (35 pts) A box m 0.75 kp) is moving on a horizontal warface with a coefficient of friction of 0.110. A spring with a spring constant of 7.25 N/m is 3.50 m from the box The box is stopped by the spring, compressing it 0.18 m A) What is the initial speed of the box? B) How fast is the box moving when it reaches the spring? Pictorial Representation What is the System? Potential Energies? Nonconservative forces? External Forces? Is Mechanical Energy conserved? Mathematical Representation

Answer 1

ar speed of block when it beach to spring mg = ₂ ke tuingue . X 0.75v1 = *7.2 5*(0:18) + 0l1X 0.75*9*8* 0• 18 Josemy work enugy theorsene ugd = { my'n Image 7 — 011X0.75X9.8% 3.5 = 4 x 0.75% 0.937?_ _ x0.75%v; 7 Vi = 2.97 uuel Km b) As calculated in 19 < my hea tu kat tuigne V = 0.837 mile system is block, spring and surface an und pofential energy = £ket espring's polentral energy Mon conservative force = friction force = ling External force = gravitational fasce ng No, mechanical energy can't be conserved. . -