Exam 1 review

PCR questions

C

\n Read through Example 8.6 in Section 8.3 before answering this question: In the example the text discusses the springs in the heel of the running shoes. Are these springs considered 'stiff" or "soft" and why?

A. The springs are considered soft because they compress by 1.2 cm during a heel strike

B. The springs are considered stiff because they compress by 1.2 cm during a heel strike

C. The springs are considered stiff because the spring constant is large, almost 300,000 N/m

D. The springs are considered soft because the spring constant is 300,000 N/m, which is a large number

B

\n In Section 8.3, the text describes Hooke's Law and provides an equation for it (page 253 if you can see page numbers, otherwise, its just above Example 8.6). Reading the equation from left to right, the three physical quantities shown in the equation are:

A. The restoring force of the spring; the spring constant; and the position of the end of the spring.

B. The restoring force of the spring; the spring constant; and the displacement of the end of the spring.

C. The force exerted on the spring; the Boltzmann constant; and the displacement of the end of the spring.

D. The spring constant; the restoring force of the spring; and the displacement of the end of the spring.

B

Read Section 8.4 and see if you can answer this question from the description there:

Complete the following statement: Young's modulus and elastic deformation cannot be applied to understand:

A. how a solid beam bends

B. how a liquid compresses

C. how bones deform

D. how a wire elongates

E

\n In section 8.4, the text provides an equation that relates "Stress" and "Strain". Complete the following statement: In general, the term stress refers to:

A. a change in length.

B. a change in volume.

C. a fractional change in length.

D. a force per unit length.

E. a force per unit area.

A

Dr. Jones demonstrates the energy transformations in an octopus spring-toy that oscillates up and down. Imagine that he let the toy continue to oscillate for a long time. The best explanation of what happens to the oscillations in terms of energy is:

A. All the energy of the toy is transformed into thermal energy and the toy stops oscillating since it has no more kinetic energy.

B. The toy stops oscillating with its total energy equally distributed between kinetic, elastic, and gravitational potential energies.

C. The toy continues oscillating with its total energy transformed into thermal energy.

D. None of the above.

1. chemical to gravitational potential

2. kinetic to thermal

3. chemical to thermal

4. elastic potential to kinetic to gravitational potential

5. work to thermal

6. work to elastic potential

1. A weightlifter lifts a barbell over her head

2. A baseball player slides into a base

3. A burning campfire

4. A springboard diver

5. Striking a match (System: match and matchbox)

6. Firing a slingshot (System: slingshot)

Options:

Chemical to Gravitational Potential

Kinetic to Thermal

Chemical to Thermal

Elastic Potential to Kinetic to Gravitational Potential

Work to Thermal

Work to Elastic Potential

heat and work

\n In section 10.1, the text identifies two ways in which energy can be transferred between a system and its environment. In alphabetical order, they are ____ and __________. Note: Each answer is a word. Make sure you place them in alphabetical order.

A, D, E

The work done on an object by a single force will necessarily be zero when (pick all the choices for which this is true)

A. The magnitude of the force acting on the object is zero

B. The force direction is parallel to the displacement of the object

C. The object moves with constant velocity

D. The force direction is perpendicular to the displacement of the object

E. The displacement of the object is zero