Which clouds are often associated with thunder and lightning?

The smallest separation resolvable by a microscope is of the order of magnitude of the wavelength used. What energy electrons would one need in an electron microscope to resolve separations of (a) 150 Angstrom (b) 5 Angstrom

A submarine begins ascending to the surface of the ocean. It experiences an overall acceleration of 1.7m/s^2 for the first 5s. What is it's velocity after 3.2 s?

An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 491 Hz when the train is approaching him and 472 Hz when the train is receding from him.

A 1-kg ball is thrown at 10 m/s straight upward. neglecting air resistance, the net force that acts on the ball when it is half way to the top of its path is about

A sunbather is lying on a floating raft that is staionary. She then gets up and walks to one end of the raft. Consider the sunbather and raft as an isolated system.

A wave with a frequency of 30 Hz has a wavelength of 40.5 m. How fast is the wave traveling?

A soccer ball is sitting in the middle of a soccer field during a game. When the referee blows his whistle, one of the players runs toward the ball and kicks it as hard as he can.

A body with v=20m/s changes its speed to 28m/s in 2sec. its acceleration will be

Charge: A piece of plastic has a net charge of + 2.00 μC. How many more protons than electrons does this piece of plastic have? (e = 1.60 * 10-19 C)

How much heat is needed to raise the temperature of 6g of water by 18oC?