Work, Energy And Power: Kinetic And Potential Energies

Question 1

What does the gradient on a f-e graph represent

Answer 1

Force constant (k)

Question 2

What does the area under a f-e graph represent

Answer 2

The work done on the spring

Question 3

What does a f-e graph look like

Answer 3

Straight line through the origin showing proportionality

Question 4

What is Hooke’s Law

Answer 4

Force is proportional to extension given that the force is constant

Question 5

What does the force constant measure

Answer 5

Stiffness of the spring

Question 6

When is Hooke’s Law not applicable

Answer 6

When the spring has stretched further than the elastic limit

Question 7

What does it mean to go beyond the elastic limit

Answer 7

Plastic deformity- cannot go back to its original length

Question 8

What is elastic deformation

Answer 8

When the deforming force is removed, the object will return to its original shape

Question 9

What is plastic deformity

Answer 9

When the deforming force is removed, the object will not return to its original shape

Question 10

What are the two types of spring

Answer 10

Compression and tension
Compressive extension and tensile extension

Question 11

What to remember when defining plastic/elastic deformation

Answer 11

When the deforming force is removed

Question 12

Why does a f-e line curve

Answer 12

It has gone beyond the limit of proportionality

Question 13

What is an example of an object that has elastic properties but doesn’t obey Hooke’s Law

Answer 13

Elastic band

Question 14

Two identical spring are attached in series.
Same tension and same extension. What is the spring constant in terms of k?

Answer 14

1/2

(k)=1/2k x 2k

The extension has doubled so k must halve to make the equation true

Question 15

Identical springs. Weight evenly distributed with same extension. What is force constant in terms of k

Answer 15

2k

force is divided by 2, extension halves, k doubles

F is proportional to e given that k is constant