phsx205_hw07a_solutions

# phsx205_hw07a_solutions - Phys 205 Chapter 7 Solutions(Part...

This preview shows pages 1–2. Sign up to view the full content.

Phys 205 Chapter 7 Solutions (Part 1) 7.20 Two objects of mass m and 3 m undergo a completely inelastic collision in one dimension. If the two objects are at rest after the collision, what was the ratio of their speeds before the collision? This is a completely inelastic collision problem. Given: Masses: m, 3 m Final velocity: v f = 0 We want to ﬁnd the ratio of their initial speeds. We can use conservation of momentum. For a completely inelastic collision, we have: m 1 v 1 i + m 2 v 2 i = ( m 1 + m 2 ) v f mv 1 i + 3 mv 2 i = 0 v 1 i = - 3 mv 2 i v 1 i v 2 i = - 3 The smaller mass will be traveling in the opposite direction as the larger mass with three times the speed. 7.21 Two particles of mass m 1 = 1 . 5 kg and m 2 = 3 . 5 kg undergo a one-dimensional head-on collision as shown in the Figure. Their initial velocities along x are v 1 i = 12 m / s and v 2 i = - 7 . 5 m / s. The two particles stick together after the collision ( a completely inelastic collision), (a) Find the velocity after the collision. (b) How much kinetic energy is lost in the collision? Fig. P7-21, p. 236 This is a completely inelastic collision problem. Given: Masses: m 1 = 1 . 5 kg , m 2 = 3 . 5 kg Initial velocities: v 1 i = 12 m / s , v 2 i = - 7 . 5 m / s (a) We want to ﬁnd their velocity after the collision. We can use conservation of momentum. For a completely

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 3

phsx205_hw07a_solutions - Phys 205 Chapter 7 Solutions(Part...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online