The two blocks are connected by a light string that passes over a frictionless pulley with a negligible mass. The 2 kg block lie
s on a rough horizontal surface with a constant coefficient of kinetic friction 0.4. This block is connected to a spring with spring constant 4 N/m. The second block has a mass of 8 kg. The system is released from rest when the spring is unstretched, and the 8 kg block falls a distance h before it reaches the lowest point. The acceleration of gravity is 9.8 m/s2 . Note: When the 8 kg block is at the lowest point, its velocity is zero. a. Calculate the falling distance h where the 8 kg blocks stops.
b. Consider the moment when the 8 kg block has descended by a distance of 21.168 m, where 21.168 m is less than h. At this moment calculate the sum of the kinetic energy for the two blocks. Answer in units of J.
No, he did not perform any work. Work is when you’re using energy which results in a force. Even though he was tired and sweaty, he did not move the boulder. So therefore he did not perform any work.
