Stress concentration and amplification happen more in the crack that is: a. long crack with more sharp edges b. long crack with more round edges c. short crack with more round edges d. short crack with more sharp edges

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?