Question 1

Which equation correctly represents Hooke's Law for the force exerted by a spring?

Accepted Answer

$$F_{sp} = -k \Delta x$$

Question 2

A spring is stretched by $$0.10\,\mathrm{m}$$ and exerts a force of $$20\,\mathrm{N}. $$What is the spring constant $$k$$?

Accepted Answer

$$k = 200\,\mathrm{N/m}$$

Question 3

In a graph of spring force $$F$$ versus displacement $$\Delta x$$, what does the slope of the line represent?

Accepted Answer

The spring constant $$k$$

Question 4

A block hangs from a spring attached to the ceiling. If the block is pulled down and released, which direction does the spring force act?

Accepted Answer

Upward, opposite to the displacement

Question 5

Why is there a negative sign in Hooke's Law $$F_{sp} = -k \Delta x$$?

Accepted Answer

Because the force opposes the direction of displacement

Question 6

If two identical springs are connected in parallel and stretched by the same amount, how does the total force compare to a single spring?

Accepted Answer

The total force is double that of a single spring

Question 7

A ligament in the knee (ACL) has a Young's modulus of $$Y = 1.0 	imes 10^9$\,\mathrm{N/m^2$}$$, a length of $$2.5\,\mathrm{cm}$$, and a cross-sectional area of $$0.40\,\mathrm{cm^2$}. If a$$ $$1500\,\mathrm{N}$$ force is applied, what is the stretch $$\Delta L$$?

Accepted Answer

$$\Delta L = 0.094\,\mathrm{cm}$$

Question 8

Which of the following best describes 'stiffness' in the context of springs?

Accepted Answer

The spring constant $$k$$, representing resistance to deformation

Question 9

A DNA strand is stretched using optical tweezers. In the linear region of the force-extension graph, which law best describes the relationship between force and extension?

Accepted Answer

Hooke's Law

Question 10

If a spring has a small spring constant, what does this indicate about the spring?

Accepted Answer

It stretches easily under small forces

Question 11

A trampoline stretches $$0.5\,\mathrm{m}$$ when a $$300\,\mathrm{N}$$ force is applied. What is the spring constant $$k$$?

Accepted Answer

$$k = 150\,\mathrm{N/m}$$

Question 12

Which of the following is the correct definition of 'strain' in the context of elasticity?

Accepted Answer

Strain is the change in length divided by the original length

Question 13

A material has a Young's modulus $$Y$$ and is subjected to a stress $$\sigma. $$What is the resulting strain $$\epsilon$$?

Accepted Answer

$$\epsilon = \frac{\sigma}{Y}$$

Question 14

If the maximum stress an ACL can withstand is $$3 	imes 10^7$\,\mathrm{N/m^2$}$$ and its cross-sectional area is $$0.40\,\mathrm{cm^2$}$$, what is the maximum force it can withstand?

Accepted Answer

$$1900\,\mathrm{N}$$

Question 15

Which of the following statements about free body diagrams is correct?

Accepted Answer

They show all the forces acting on a single object

Question 16

A spring is compressed by $$\Delta x. $$What is the direction of the spring force?

Accepted Answer

Opposite to the direction of $$\Delta x$$

Question 17

Which of the following best describes the relationship between stress and strain for an elastic material?

Accepted Answer

Stress is proportional to strain

Question 18

A spring is stretched by $$\Delta x$$ and exerts a force $$F_{sp}. If $$the spring constant $$k is $$doubled, what happens to the force for the same displacement?

Accepted Answer

The force is doubled

Question 19

Which real-world example can be modeled as a spring system according to the study materials?

Accepted Answer

The rhythm of a heartbeat

Question 20

If a spring is stretched by $$\Delta x$$ and the force $$F_{sp} is $$measured, which index best quantifies the 'stiffness' of the spring?

Accepted Answer

$$k = \frac{F_{sp}}{\Delta x}$$

Springs and Elasticity: Physics Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드