A 0.40kg mass attached to a spring is pulled back horizontally across a table so that the potential energy of the system is increased from zero to 150 J. Ignoring friction, what is the kinetic energy of the system after the mass is released and moved to a point where the potential energy has decreased to 60 J?

A particle with a mass of 2.00 kg moves along the x axis. Initially, the particle's position is x = 1.00 m and its speed is 4.00 m/s. The graph below shows the potential energy of the particle vs. position. Assume that the total mechanical energy of the particle is conserved throughout its motion. + U (Joules) 20.0 (a) What is the total mechanical energy of the particle (E = K + U), in units of Joules (J)? 15.0 – 10.0 5.00 x (meters) 1.00 2.00 3.00 4.00 -5.00 (b) What is the speed of the particle when it is located at x = 2.00 meters? Give your answer in meters per second (m/s). (c) What are the equilibrium positions of the particle? For each equilibrium position, determine whether it is stable or unstable.

A 2.03 kg mass is initially at rest upon a horizontal surface. An applied force of 17.6 N i then acts on the object over a distance of 2.92 m. If the final velocity of the object is 4.09 m/s i, what is the work done by kinetic friction over that distance moved?

In the figure, a block of mass m = 1.30 kg slides head on into a spring of spring constant k = 390 N/m. When the block stops, it has compressed the spring by 6.60 cm. The coefficient of kinetic friction between block and floor is 0.330. While the block is in contact with the spring and being brought to rest, what are (a) the work done by the spring force and (b) the increase in thermal energy of the block-floor system? (c) What is the block's speed just as the block reaches the spring?