Spend time observing or thinking about events that involve matter and energy. Which events can you explain? Which events can’t you explain? Now answer the following questions.

Part A
Describe three events that you cannot explain.

The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

1. jay fills a wagon with sand (about 20 kg) and pulls it with a rope 30 m along the beach. he holds the rope 25° above the horizontal. the rope exerts a 20-n tension force on the wagon. how much work does the rope do on the wagon?

Which body part transports oxygen removes waste materials in carries nutrients to the body as part of the circulatory system