Ultrasound is sound that has a wave frequency higher than which is higher in frequency than the human ear can
detect.
a 22,000 hertz
b 18,000 hertz
C 20,000 hertz
d 12,000 hertz

Athin, square metal plate measures 14 cm on each side and has emissivity of 0.60. the plate is heated to a temperature of 745°c. what is the rate at which the plate radiates energy ? the stefan-boltzmann constant is 5.67 × 10-8 w/(m2 ? k4). remember that the plate will radiate energy from both its top and bottom surfaces.

Asmall, positively charged ball is moved close to a large, positively charged ball. which describes how the small ball likely responds when it is released? it will move toward the large ball because like charges repel. it will move toward the large ball because like charges attract. it will move away from the large ball because like charges repel. it will move away from the large ball because like charges attract.

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration