An electromagnetic wave of wavelength 435 nm is traveling in vacuum in the –z direction. the electric field has an amplitude of 2.70×10−3v/m and is parallel to the x axis. what are the frequency and the magnetic-field amplitude of this wave?

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

Which type of reaction is shown in this energy diagram? energy products activation energy reactants time o a. endothermic, because energy is released to the surroundings o b. exothermic, because energy is absorbed from the surroundings o c. exothermic, because energy is released to the surroundings o d. endothermic, because energy is absorbed from the surroundings

An alpha particle with kinetic energy 12.5 mev makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude l = p0 b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.40×10−12 m. (assume that the lead nucleus remains stationary and that it may be treated as a point charge. the atomic number of lead is 82. the alpha particle is a helium nucleus, with atomic number 2.) what is the distance of closest approach?