An athlete is running a 5-km race at an average speed of 8 km/h. She has to stop to tie her shoe. After tying her shoe, she continues running at 8 km/h. Why would her average speed for the entire race be less than 8 km/h?

What is the mass of the same rock on the earth

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?

Ais not a mixture. colloid compound suspension solution