PRACTICE IT Use the worked example above to help you solve this problem. The ballistic pendulum (Figure a) is a device used to measure the speed of a fast-moving projectile such as a bullet. The bullet is fired into a large block of wood suspended from some light wires. The bullet is stopped by the block, and the entire system swings up to a height h. It is possible to obtain the initial speed of the bullet by measuring h and the two masses. As an example of the technique, assume that the mass of the bullet, m₁, is 5.35 g, the mass of the pendulum, m2, is 1.097 kg, and h is 4.54 cm. (a) Find the velocity of the system after the bullet embeds in the block. m/s (b) Calculate the initial speed of the bullet. m/s EXERCISE HINTS: GETTING STARTED I'M STUCK! A bullet with mass 5.06 g is fired horizontally into a 1.981-kg block attached to a horizontal spring. The spring has a constant 5.84 x 10² N/m and reaches a maximum compression of 6.19 cm. (a) Find the initial speed of the bullet-block system. m/s (b) Find the speed of the bullet. m/s

College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
icon
Related questions
Topic Video
Question
GOAL Combine the concepts of conservation of energy and conservation of momentum in inelastic
collisions.
PROBLEM The ballistic pendulum (Figure a) is a device used to measure the speed of a fast-moving
projectile such as a bullet. The bullet is fired into a large block of wood suspended from some light wires.
The bullet is stopped by the block, and the entire system swings up to a height h. It is possible to obtain
the initial speed of the bullet by measuring h and the two masses. As an example of the technique,
assume that the mass of the bullet, m₁, is 5.00 g, the mass of the pendulum, m2, is 1.000 kg, and h is
5.00 cm. (a) Find the velocity of the system after the bullet embeds in the block. (b) Calculate the initial
speed of the bullet.
STRATEGY Use conservation of energy to find the initial velocity of the block-bullet system, labeling it
Vsys. Part (b) requires the conservation of momentum equation, which can be solved for the initial velocity
of the bullet, V₁i.
SOLUTION
(A) Find the velocity of the system after the bullet embeds in the block.
(KE+ PE) after collision
Apply conservation of energy to the
block-bullet system after the collision.
Substitute expressions for the kinetic
and potential energies. Note that both
the potential energy at the bottom and
the kinetic energy at the top are zero.
Solve for the final velocity of the
block-bullet system, vsys
(B) Calculate the initial speed of the bullet.
Write the conservation of momentum
equation and substitute expressions.
Solve for the initial velocity of the
bullet, and substitute values.
2
(m₁ + m₂) v sys² + 0 = 0 + (m₁ + m₂)gh
V sys
Vsys
V sys
=
=
=
V1i =
V₁; =
2gh
=
m₁v₁i + m₂V2i =
=
✓ 2gh 2(9.80 m/s²) (5.00 × 10-² m)
0.990 m/s
Pi Pf
(KE + PE) top
(m₁ + m₂) v sys
(m₁ + m₂) v sys
m₁
(1.005 kg)(0.990 m/s)
= 199 m/s
Transcribed Image Text:GOAL Combine the concepts of conservation of energy and conservation of momentum in inelastic collisions. PROBLEM The ballistic pendulum (Figure a) is a device used to measure the speed of a fast-moving projectile such as a bullet. The bullet is fired into a large block of wood suspended from some light wires. The bullet is stopped by the block, and the entire system swings up to a height h. It is possible to obtain the initial speed of the bullet by measuring h and the two masses. As an example of the technique, assume that the mass of the bullet, m₁, is 5.00 g, the mass of the pendulum, m2, is 1.000 kg, and h is 5.00 cm. (a) Find the velocity of the system after the bullet embeds in the block. (b) Calculate the initial speed of the bullet. STRATEGY Use conservation of energy to find the initial velocity of the block-bullet system, labeling it Vsys. Part (b) requires the conservation of momentum equation, which can be solved for the initial velocity of the bullet, V₁i. SOLUTION (A) Find the velocity of the system after the bullet embeds in the block. (KE+ PE) after collision Apply conservation of energy to the block-bullet system after the collision. Substitute expressions for the kinetic and potential energies. Note that both the potential energy at the bottom and the kinetic energy at the top are zero. Solve for the final velocity of the block-bullet system, vsys (B) Calculate the initial speed of the bullet. Write the conservation of momentum equation and substitute expressions. Solve for the initial velocity of the bullet, and substitute values. 2 (m₁ + m₂) v sys² + 0 = 0 + (m₁ + m₂)gh V sys Vsys V sys = = = V1i = V₁; = 2gh = m₁v₁i + m₂V2i = = ✓ 2gh 2(9.80 m/s²) (5.00 × 10-² m) 0.990 m/s Pi Pf (KE + PE) top (m₁ + m₂) v sys (m₁ + m₂) v sys m₁ (1.005 kg)(0.990 m/s) = 199 m/s
PRACTICE IT
Use the worked example above to help you solve this problem. The ballistic pendulum (Figure a) is a
device used to measure the speed of a fast-moving projectile such as a bullet. The bullet is fired into a
large block of wood suspended from some light wires. The bullet is stopped by the block, and the entire
system swings up to a height h. It is possible to obtain the initial speed of the bullet by measuring h and
the two masses. As an example of the technique, assume that the mass of the bullet, m₁, is 5.35 g, the
mass of the pendulum, m2, is 1.097 kg, and h is 4.54 cm.
(a) Find the velocity of the system after the bullet embeds in the block.
m/s
(b) Calculate the initial speed of the bullet.
m/s
HINTS: GETTING STARTED I I'M STUCK!
A bullet with mass 5.06 g is fired horizontally into a 1.981-kg block attached to a horizontal spring. The
spring has a constant 5.84 x 10² N/m and reaches a maximum compression of 6.19 cm.
EXERCISE
(a) Find the initial speed of the bullet-block system.
m/s
(b) Find the speed of the bullet.
m/s
Transcribed Image Text:PRACTICE IT Use the worked example above to help you solve this problem. The ballistic pendulum (Figure a) is a device used to measure the speed of a fast-moving projectile such as a bullet. The bullet is fired into a large block of wood suspended from some light wires. The bullet is stopped by the block, and the entire system swings up to a height h. It is possible to obtain the initial speed of the bullet by measuring h and the two masses. As an example of the technique, assume that the mass of the bullet, m₁, is 5.35 g, the mass of the pendulum, m2, is 1.097 kg, and h is 4.54 cm. (a) Find the velocity of the system after the bullet embeds in the block. m/s (b) Calculate the initial speed of the bullet. m/s HINTS: GETTING STARTED I I'M STUCK! A bullet with mass 5.06 g is fired horizontally into a 1.981-kg block attached to a horizontal spring. The spring has a constant 5.84 x 10² N/m and reaches a maximum compression of 6.19 cm. EXERCISE (a) Find the initial speed of the bullet-block system. m/s (b) Find the speed of the bullet. m/s
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

Blurred answer
Knowledge Booster
Momentum
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON