An isolated conducting sphere of radius R having charge Q uniformly distributed on its surface in electrostatic equilibrium. What is the electric flux (ΦE ) through a concentric spherical surface of radius 3R? Hint: ∈0 is the permitivity of free space.

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

Talia is manufacturing rolls of wire for hanging pictures. she needs a material that is so that it can easily be pulled into wire without breaking.

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?