Physics Hw Help?

Question

Three masses, m1=500 g, m2=1000 g, and m3=1500 g, are attached by strings that run over massless, frictionless pulleys. The horizontal surface is frictionless, and the system is released from rest. Find the velocity of the 1500 g block after it moves 120 cm.

Answer 1

Mass of the 1st object = 500 g = 0.5 kg

Mass of the 2nd object = 1000 g = 1kg

Mass of the 3rd object = 1500 g = 1.5kg

Displacement  = 120 cm

From the law of conservation of Energy.

Where is the work done by the 1500g block.

Work done by m3 object = Force * Distance traveled.

Force by the object traveling along the smooth surface = mg

Force = m g.

F = 1.5 * 9.8

F = 14.7 N

= F * s

Where S is the displacement

= 14.7 * 120 * 10^-2

= 17.640

Now substitute it in law of conservation of Energy.

v² = 11.76

v = 3.429 m/sec

Therefore the velocity of the 1500g block is 3.429 m/sec.