How does lightning occur?

The sphere that refers to Earths water is called the

a. Charles designed a system to pull sleds uphill, but he needs to know the angle of the slope. He knows that the hill is 13 m high and that the distance from the base of the hill to the top is 20 m. i. Calculate the angle of the slope. b.

When two solid objects are put in direct physical contact with each other, which is the primary method of heat transfer between the objects?

A mystery substance is found to be a very strong base. What will its pH most likely be?

Metallic bonds are important to how paperclips are both made and used. Which statement best describes how metallic bond properties are important for making and using paperclips?

A rock is thrown downward into a well that is 7.92 m deep. Part A If the splash is heard 1.17 seconds later, what was the initial speed of the rock? Take the speed of sound in the air to be 343 m/s.

Which drum would make a sound that fades away faster - one that makes a loud sound or one that makes a more mellow sound Why?

Which of the following is NOT a way to increase the solubility of a solid in water? A. crushing the solid B. shaking the mixture of solid and water C. raising the temperature of the water D. letting the mixture stand still a long time

Which of the following is true about cells? A. Cells have specialized components that perform different, specific functions. B. A cell's components are all identical and perform the same function. C.

How much heat is contained in 100 kg of water at 60.0 °C?