What is electricity? Why does it happen?

A cable applies a vertical force to a crate with a mass of 70.0 kg. It first lifts the crate to a height of 12.0 m above the floor, and then lowers it back to the floor. What is the total work done by the force?

How much force is needed to stop a 80-kg football player if he decelerates at 5 m/s2

Compare and Contrast Potential Energy with Thermal Energy

A dolphin in seawater at a temperature of 25°C emits a sound wave directed toward the ocean floor 154 m below. How much time passes before it hears an echo? (The speed of sound in ocean water is 1533 m/s.)

For each of the following news stories, determine whether the objects speed or velocity is given: the world record for the hundred-meters dash is about 10m/s; the wind today is 30 km/h from the north-west;

What factors affect the speed of a wave?

What direction does air resistance act on an object that is falling straight down

How are the relationships of elements in a group different from the relationships of elements in a period?

Children in a tree house lift a small dog in a basket 4.00 m up to their house. If it takes 187 J of work to do this, what is the combined mass of the dog and basket?

What happens to the speed of the particles if the temperature is increased