A light wave from a star has a frequency of 6.67 * 100 Hz and a wavelength of 4.50 x 10 to the power of -7 m. The star is 4.00 * 10 to the power of 16 m away from Earth.
Calculate the time it takes light from the star to reach the Earth.

Lets say that an object of a certain volume has a certin mass. what happens to its mass when you double its volume?

Bernie drove home from a vacation in 1.5 hours. he traveled a total distance of 60 miles. what was his average speed in miles per hour? a. 60 mph b. 90 mph c. 40 mph d. 55mph

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.