An electron (with charge q and mass m) enters a uniform magnetic field b. this electron shows a helical motion with a radius r, and a pitch h. (a) what is the direction of the magnetic field? use the coordinate system provided. (b) if we double the field strength, how would the helical motion change? radius: increases [ ], stays the same [ ], decreases [ ] pitch: increases [ ], stays the same [ ], decreases [ ] (c) find the symbolic expression for the speed of the electron

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?

What is the mass of the water that is being heated? it requires 2,500 joules to raise a certain amount of water (c = 4.186 jig c) from 20.0°c to 60.0°c. o 159 o 40 g o 63 g o 80 g