The total momentum of a flock of identical birds could be zero only if the birds

Question

The total momentum of a flock of identical birds could be zero only if the birds are A) flying in the direction B) very tired and coming down to rest. C)taking off from the ground. D) flying in different directions. 37) The planet Jupiter is about 300 times as massive as Earth. yet on its surface you would weigh only bout 3 times as much because A) Jupiter's radius is about 10 times Earth's radius. B) you are 100 times mote weightless there C) your mass is 100 times less on Jupiter. D) Jupiter is significantly farther from the Sun. E) none of the above. Which has zero acceleration? An object A) moving at constant velocity. B) at rest. C) in mechanical equilibrium. D) all of the above E) none of the above If you toss a coin straight upward while in a train moving at constant velocity, the coin will land A) as if you were at rest. B) in front of you. C) in back of you. A hockey pock is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is A) equal to its mass times its weight B) equal to its weight. C) equal to its weight divided by its mass. D) none of the above Nellie tosses a bail upward at an angle. Neglecting air resistance, the vertical component of the initial velocity A) increases with time to reach the top. B) decreases with time to reach the top. C) remains constant. The vertical height attained by a basketball player who achieves a hang time of a full 1 s is about A) 25 m. B)l.2m. C) 1 m. D) 0.8 m. E) more than 25 m. A golf ball moving forward with 1 unit of momentum strikes and bounces backward off a heavy bowling ball that is initially at rest and free to move. The bowling ball is set in motion with a momentum of A) less than 1 unit. B) 1 unit C) more than 1 unit. D) not enough information An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the Earth, its speed one second later would be A) 10 m/s. B) 20 m/s. C) 30m/s. D) 40m/s.

Explanation / Answer

36. Option is (d), because when birds are flying in different directions their velocities will point in different directions to give the net vector sum equals to zero.

38. (d) As the acceleration will be zero either when the object is at rest or change in velocity of the object is zero or net force acting on the object is zero.

41. (B) When we project a body upward its vertical component goes on decreasing until it becomes zero at the topmost point, due to gravity while the horizontal component remains constant.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.