I'm having a bit of a problem with these homework questions, if anyone could help out that would be great!! 1. A 15 kg mass is attached to a massless spring by a light string that passes over a frictionless pulley. The spring has a force constant k= 500 N/m and is unstretched when the mass is relased. What is the velocity when it has fallen a distance of .30 m? 2. A 0.75 kg sphere is dropped through a tall column of liquid. When the sphere has fallen a distance of 2.0 m, it is observed to have a velocity of 2.5 m/s a. how much work was done by the frictional force exerted on the sphere by the liquid? b. what is the average force of friction during the displacement of 2.0 m? I am completely stumped, =( please help!!