A 3-kg mass moving at 10 m/s collides with a stationary 2-kg mass. After the col

Question

A 3-kg mass moving at 10 m/s collides with a stationary 2-kg mass. After the collision, the 3-kg mass is moving at 4 m/s. The collision lasts 0.25 sec. What is the final velocity of the 2-kg mass How far from the collision-point was the center of mass of the system 2 seconds before the collision Calculate the impact force on the 3-kg mass directly from the given data: Calculate the impact force on the 2-kg mass from the given data and your answer to part (a): Are your answers to parts (c) and (d) related in the expected way (Yes / No) Explain: The gravitational acceleration at the surface of a certain planet is 48 m/s^2. Calculate the weight of (the gravitational force on) a 2-kg object at the surface.

Explanation / Answer

12.

a) using momentum conservation for this collision,

3*10 + 2*0 = 3*4 + 2*v

v = 9 m/s

b) before 2 sec 3kg mass was 20 m from 2 kg mass.

Xcm = (m1x1 + m2x2) / (m1 + m2)

Xcm = ( 3*20 + 2*0) / (3 + 2)   = 12 m

c) Impulse = change in momentum = 3 ( 4 - 10) = 18 kgm/s

Impulse =F x deltat

18 = F x 0.25

F = 72 N

d) Impulse = 2 x (9 - 0 ) = 18 kg m /s

18 = F x 0.25

F = 72 N

e) Yes,

from the newton's third law.

(action reaction pair - same in magnitude but opposite in direction)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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