Două mobile se mişcă rectiliniu şi uniform, după legile x1= 2·t + 5 şi x2=-2·t +9. Momentul de timp (exprimat în secunde) la care cele două mobile se întâlnesc este: *

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Matter that emits no light at any wavelength is called

The brightest star in the night sky in the northern hemisphere is sirius. its distance from earth is estimated to be 8.7 light years. a light year is the distance light travels in one year. light travels at a speed of 3.00 × 108 m/s. calculate the distance from earth to sirius in miles. (1 mi = 5280 ft) g