An electret is similar to a magnet, but rather than being permanently magnetized, it has a permanent electric dipole moment. suppose a small electret with electric dipole moment 1.0 × 10−7 cm is 25 cm from a small ball charged to + 80 nc, with the ball on the axis of the electric dipole. what is the magnitude of the electric force on the ball?

To travel at constant speed, a car engine provides 24kw of useful power. the driving force on the car is 600n. at what speed does it travel?

The table below shows the acceleration of gravity on different bodies in the solar system. on which body would a 10 kg lamp has the most gravitational potential energy when lifted to a height of 2 m? a. earth b. mars c. neptune d. uranus

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.