Lightning flashed, and after 7 seconds there was a roll of thunder. To the nearest meter, determine how far lightning flashed from us,
if the speed of sound is 337 m / s.

Atennis player used a tennis racket to hit a tennis ball with a mass of 0.25 kg with a force of 5.25 newtons. how does the force the tennis racket exerted on the tennis ball compare with the force the tennis ball exerted on the tennis racket? a. the force of the tennis racket on the tennis ball is equal in magnitude and opposite in direction to the force the tennis ball exerted on the tennis racket. b. the force of the tennis racket on the tennis ball is equal in magnitude and in the same direction as the force the tennis ball exerted on the tennis racket. c. the force of the tennis racket on the tennis ball is less in magnitude and in the same direction as the force the tennis ball exerted on the tennis racket. d. the force of the tennis racket on the tennis ball is greater in magnitude and opposite in direction as the force the tennis ball exerted on the tennis racket.

The topics covered by the study of thermodynamics include a. energy changes during heating. b. energy changes during chemical reactions. c. color changes during chemical reactions. d. both (a) and (b)

In a 1.25-t magnetic field directed vertically upward, a particle having a charge of magnitude 8.50 mc and initially moving northward at 4.75 km> s is deflected toward the east. (a) what is the sign of the charge of this particle? make a sketch to illustrate how you found your answer. (b) find the magnetic force on the particle.