Bộ tài liệu bài tập tham khảo môn vật lý bậc đại học bằng tiếng anh Chapter 08 | a 10 000 kg m s x 105 kg m s. b i Five times the speed ms. ii V5 m s ms. See Exercise a the iceboats have the same kinetic energy so the boat with the larger mass has the larger magnitude of momentum by a factor of 4 2m m 42. a r 1 2 K mv 2 22 1 m2v2 2 m 1 pL 2 m 2 2 p P b From the result of part a for the same kinetic energy so the larger mass m1 m2 baseball has the greater momentum pbird pball . From the result of part b for the same momentum K1m1 K2m2 so K1 w1 K2w2 the woman with the smaller weight has the larger kinetic energy. Kman K woman 450 700 . From Eq. Px mvx kg s cos kg m s Py mvy kg ms sin kg ms. The y-component of the total momentum is kg ms kg - ms kg ms. This quantity is negative so the total momentum of the system is in the - y -direction. From Eq. py - kg m s kg ms and Px kg ms kg m s so the total momentum has magnitude P 7PX Py 7 - kg ms 2 kg ms 2 kg ms 10 nt 1 o fri zù 1 I 1-015 1 2 QO 11 fin ex 4 1 1 zù t mil iû 4 1 1 zù 1 t 4 1 i 4- -fi i-t 4 1 vi i 1 4-1- and is at an angle arctan -68 using the value oi the arctangent function in the fourth quadrant px 0 py 0 . f 25 ms 563 N. The weight of the ball is less than half a newton so the Ai lo 3 s b weight is not significant while the ball and club are in contact. a The magnitude of the velocity has changed by s - - ms ms and so the magnitude of the change of momentum is kg ms kg ms to three figures. This is also the magnitude of the impulse. b From Eq. the magnitude of the average applied force is 14-500kgf s x 103N. a Considering the x-components P2 P1 J kg ms N x s kg ms and the velocity is ms in the x-direction. b p 2 kg m s N s kg ms and the velocity is .
