A commercial diffraction grating has 300 lines per mm. When a student shines a 470 nm laser through this grating, how many bright spots could be seen on a screen behind the grating

A175 g lump of molten lead at its melting point (327 c) is placed into 55.0 g of water at 20.0 c. the specific heat of lead is 130.j/kg c and the hf of lead is 20,400 j/kg. when the lead and the water have reached equilibrium, what is the temperature of the mixture?

How does an observation about an object differ from an inference about that object

The electric field direction is defined by the direction of the force felt by (select one of the following answers): 1. a negative charge. 2. a positive charge. 3. both positive and negative charges.