Athin spherical shell with radius r1 = 4.00 cm is concentric with a larger thin spherical shell with radius r2 = 6.00 cm . both shells are made of insulating material. the smaller shell has charge q1=+6.00nc distributed uniformly over its surface, and the larger shell has charge q2=−9.00nc distributed uniformly over its surface. take the electric potential to be zero at an infinite distance from both shells.

When you drop a pebble from height a it reaches the ground with speed v if there is no air resistance. from what height should you drop it so it will reach the ground with three times the speed? (a) 9m (b) 3m (c) 6m (d) 18m

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?