Question

The lumberjack and his log Jack, the lumberjack, mass mj, is standing on his favorite log, mass mi, which is floating motionless on the lake. He starts running on the log, reaching a speed of vJJL- 3 m/s, the subscript indicating that it is measured with respect to the log. What is Jack's speed with respect to the shore vjs? Hint: Use Galilean velocity transformations In peace... A cannon is firing shells of mass m, at a muzzle velocity v and at a rate of n rounds per scconds a) Determine the average recoil force F b) We apply this answer to the 30 mm Gatling cannon mounted on the A-10 Thunderbolt aircraft, nicknamed "the tank killer", also "the warthog" in view of its ungainly look This powerful gun can fire the 0.680 kg shells at a rate of 3900 rounds per minute with a supersonic muzzle velocity of 1000 m/s. The mass of the aircraf s M -20, 000 kg. It is powered by two turbofans, each delivering a maximum thrust of 40kN. i) Calculate the average recoil force that the gun applies to the aircraft. Compare to the engine maximum thrust ii) The cannon is normally fired in 2 s bursts. By how much will the speed of the aircraft decrease, if full engine thrust (which balances drag) is maintained?

Answer 1

Ans- C ly Thrust balance olT04 -Lec01· totce 20 olecteale in speed 4.42 ms