In a thundercloud there may be an electric
charge of 47 C near the top and −47 C near
the bottom. These charges are separated by
approximately 1.8 km.
What is the magnitude of the electric force
between them? The Coulomb constant is
8.98755 × 10^9 N · m^2
/C^2
.
Answer in units of N.

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.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration