Câu 23. Một viên đạn đang bay thẳng đứng lên cao, khi lên tới điểm cao nhất thì viên đạn bị nổ thành 2 mảnh có khối lượng lần lượt là m và 2m. . Biết tổng động năng của 2 mảnh ngay sau khi nổ là 9000J. Động
năng mảnh đạn có khối lượng m ngay sau khi nổ là
A. 4000J.
B. 2000J . C. 8000J.
D. 6000J.

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

6–55 refrigerant-134a enters the condenser of a residential heat pump at 800 kpa and 358c at a rate of 0.018 kg/s and leaves at 800 kpa as a saturated liquid. if the compressor consumes 1.2 kw of power, determine (a) the cop of the heat pump and (b) the rate of heat absorption from the outside air.

During the apollo moon missions, astronauts were concerned about the effects of newton's third law of motion when: o a. they ejected waste water, because they were concerned that it would push them off course. o b. they reentered earth's atmosphere, because they were carrying heavy moon rocks. o c. they took off from earth, because a large force was required to generate large acceleration. o d. they detected incoming space debris, because the inertia of the debris could damage their ship.