How fast is a ball going when it hits the ground after being dropped from a height of 9 m? The acceleration of gravity is 9.8 m/s2
O A. 17.6 m/s
O B. 14.9 m/s
O C. 11.5 m/s
O D. 13.3 m/s

Help !

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?

Only 3% of the water on earth is usable by humans. even though that 3% is through the water cycle, we still need to be careful not to waste water.

2) the sun is wonderful source of energy. it is renewable and natural with few dangers. solar cells rely on the sun for energy. these cells would be more practical to use if they were