in which of the following scenarios does acceleration occur?
a child gets on a bicycle and begins pedaling down the sidewalk.
b. awoman walks toward a grocery store then turns around and walks bac
c. a car moving up a road slows down and stops at a red light.
d. all of these

Ajet plane has a sound level of 120 db at a distance of 60 m. what is the q23. sound level at a distance of 6.0 km? (60)2 (6000)? om solution 80db db, hint: 16x assume ultrasound waves travel through the body of an animal at 1540 q24. m/s. if a 30,000 hz signal were reflected off a portion of a heart which was moving toward the source at 3 m/s, what frequency signal would return to the stationary source? solution 30.117hz

The image below shows numerous volcanic mountains in the pacific northwest. what is the most likely cause of the volcanic and earthquake activity in this region?

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?