Acharged cloud system produces an electric field in the air near earth's surface. a particle of charge -2.0 × 10-9 c is acted on by a downward electrostatic force of 4.3 × 10-6 n when placed in this field. (a) what is the magnitude of the electric field? (b) what is the magnitude of the electrostatic force on a proton placed in this field? (c) what is the gravitational force on the proton? (d) what is the ratio of the electrostatic force to the gravitational force in this case?

Two technicians are discussing a resistance measurement between the can-h and can-l wires. technician a says this measurement should be done with the ignition switch in the "run" position. technician b states that a measurement of 0 ohms indicates an open in the network. which technician is correct?

Astudent is performing an experiment comparing sound and light waves. the student gathers the following data. what conclusion does the student most likely make based on this data? light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through. all sound waves always have the same energy, so the temperature of the medium does not affect wave speed. light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas. tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

Amodel rocket with a mass of 0.212 kg is launched into the air with an initial speed of 84 m/s. how much kinetic energy will the rocket have at a height of 214 m? assume there is no wind resistance. 634 j 303 j