15-134. A rocket has an empty weight of 500 lb and carries 300 lb of fuel. If the fuel is burned at the rate of 15 lb/s and ejected with a relative velocity of 4400 ft/s, determine the maximum speed attained by the rocket starting from rest. Neglect the effect of gravitation on the rocket.

The missile weighs 47000 lb. The constant thrust provided by the turbojet engine isT = 18000 lb. Additional thrust is provided by two rocket boosters B. The propellant ineach booster is burned at a constant rate of 175 lb/s, with a relative exhaust velocity of 2000f t/s. If the mass of the propellant lost by the turbojet engine can be neglected, determinethe velocity of the missile after the 6 s burn time of the boosters. The initial velocity ofthe missile is 150 mi/h. Using your integration procedure from the previous labs solve thisproblem with n = 5, n = 10 and n = 100.

A railroad car having a mass of 15000 kg is coasting at 1.5 m/s on a horizontal track. At the same time another car having a mass of 12000 kg is coasting at 0.75 m/s in the opposite direction. If the cars meet and couple together, determine the speed of both cars just after the coupling.

The motor, M, pulls on the cable with a force F = (101² + 300)N, where t is in seconds. If the 100 kg crate is originally at rest at 1 = 0, determine its speed when t = 4 s. Hint: First find the time needed to begin lifting the crate.