Electromagnetic radiation with a wavelength of 725 nm appears as red light to the human eye. The energy of one photon of this light is 2.74 × 10-19 J. Thus, a laser that emits 1.3 ×10-2 J of energy in a pulse of light at this wavelength produces photons in each pulse.

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

A2.00-m long piano wire with a mass per unit length of 12.0 g/m is under a tension of 8.00 kn. what is the frequency of the fundamental mode of vibration of this wire?

What is the power rating of the lightbulb if 3.0 a flow through it when connected to a 15 v battery