a magnetic rail gun is constucted to give a space vehicle its intial launch velocity, thereby reducing the amount of fuel the vehicle has to carry. it consist of two very long parallel rails across which is positioned a large current carrying crossbar 7.65 m long. The crossbar and its payload (combined mass=2940 kg) will accelerate due to the magnetic force exerted on the current in the crossbar. Perpendicular to the plane of the rails and crossbar is a constant magnetic filed of 1.25 T. A steady current of 6600 A is maintained in the crossbar and rails. Find the magnetic force exerted on the bar, and from it the accerleration of the combined bar and payload.

Question

a magnetic rail gun is constucted to give a space vehicle its intial launch velocity, thereby reducing the amount of fuel the vehicle has to carry.  it consist of two very long parallel rails across which is positioned a large current carrying crossbar 7.65 m long. The crossbar and its payload (combined mass=2940 kg) will accelerate due to the magnetic force exerted on the current in the crossbar. Perpendicular to the plane of the rails and crossbar is a constant magnetic filed of 1.25 T. A steady current of 6600 A is maintained in the crossbar and rails. Find the magnetic force exerted on the bar, and from  it the accerleration of the combined bar and payload.

Elena · Answer

F=ILBsinα sinα=sin 90⁰=1 => F=ILB =6600•7.65•1.25 =6.31 •10⁴ N F=ma => a=F/m= 6.31 •10⁴/2940 = 21.5 m/s².