An electromagnet is made by inserting a soft iron core into a solenoid. The solenoid has 1800 turns, radius 2.00 cm, and length 16.6 cm. When 2.00 A of current flows through the solenoid, the magnetic field inside the iron core has magnitude 0.620 T. What is the relative permeability KB of the iron core?

Find the resultant force on (a) the mass m_{1} = 0.184kg and (b) the mass m_{2} = 0.107 kg in the figure below (the masses are isolated from the earth) fm1= ? Fm2=?

An astronaut is a short distance from her space station without a tether rope or jet pack. She does have a large wrench. To move herself toward the space station she could, a) throw the wrench directly toward the station, b) throw the wrench parallel to the orbit of the station, c) throw the wrench away from the station or d) throw the wrench toward the space station without letting go of it.

An object weighs 90 N on Earth’s surface. Determine its weight when it is two Earth radii from the planet’s surface.