Hey I need help with these electromagnets question ( 4 and 5). Thank you

4. You create an electromagnet by winding some coil around a ferromagnetic material such as Nickel. The coils are tightly would, and you are able to get 150 coils around this core. Using some batteries, you have lying around, you are able to produce a current of 550 mA, and are able to lift a 750g mass. a) Realizing that iron is a better material for the core, determine the force that it can produce if the magnetic field strength increases by 35%. b) If you wanted to produce a force of 12N, determine the current you would have to supply with either core. c) Instead of supplying more current, you decide to wind more loops around the core. If you add an extra 75 windings, determine the force produced by the electromagnet with the Nickel core. 5. The electromagnets used to lift cars obviously need to be capable of lifting large masses. A car with a mass of 1500kg is hoisted up by winding the core with 750 loops and supplying it with a current of 125A. a) Determine the current required to lift the same mass, if the core had 1200 windings. b) Determine the new force produced if you doubled both the number of lops and supplied current. c) Determine the new force produced if you increased the current by a factor of 1.5 and added an additional 250 windings