29. If a body moves in such a way that its linear momentum is constant, then a)

Question

29. If a body moves in such a way that its linear momentum is constant, then a) Its kinetic energy is zero b) The sum of all the forces acting on it must be zero c) The acceleration is greater than zero and is constant d) The center of mass remains at rest e) The sum of all the forces acting on the body is constant and nonzero 30. A particle of mass 2m is moving to the right in projectile motion. At the top of its trajectory, an explosion breaks the particle into two cqual parts. After the explosion, one part falls straight down with no horizontal a) motion. isthe direction of motion of the other part just after the explosion? Up the left b) Stops moving c) Up and to the right d Straight up e) Down and to the right 31. A 40 kg girl standing at rest on the ice, gives a 60 kg boy, who is also standing at rest on the ice, a shove. After the shove, the boy is moving backward at 2.0 m/s ignore friction. The girls speed is a Zero b) 1.3 m/s c 2.0 m/s d) 3.0 m/s e) 6.0 m/s 32. A bullet, m -0.500 kg, traveling with a velocity of 100 m/s strikes and embeds itself in the bob of a ballistic pendulum, M-9.50 kg. The combined masses rise to a height h 1.28 m. The speed Vr of the combined masses immediately following impact is A) B) 5.26 m/s D) 10.0 m/s E) 22.3 m/s 33. A boy and a girl are riding on a merry go round which is tuming at a constant rate. The boy is near the a) outer edge, and the girl is closer to the center. Who has the greater angular displacement? The boy b The girl c) Both have the same non zero angular displacement d) Both have zero angular displacement

Explanation / Answer

Number 29)

Choice B

Number 30)

Choice C

Number 31)

Conservation of momentum

mv = mv

40(v) = 60(2)

v = 3 m/s (Choice D)

Number 32)

By conservation of energy

mgh = .5mv2 (mass cancels)

(9.8)(1.28) = .5(v)2

v = 5.00 m/s (Choice A)

Number 33)

Choice C

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

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