The vlba (very long baseline array) uses a number of individual radio telescopes to make one unit having an equivalent diameter of about 8000 km. this radio telescope is focusing radio waves of wavelength 2.0 cm. what would have to be the diameter of the mirror of a visible-light telescope focusing light of wavelength 582 nm so that the visible-light telescope has the same resolution as the radio telescope? give an answer in m. pay attention to the number of significant figures.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 2 options: the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the cold balloon expands and rises. the warm balloon shrinks and sinks. the warm balloon expands and rises. the cold balloon shrinks and sinks.

Explain why electric current cannot exist if a current doesn't have a voltage source.

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell