1.4 Effects of Forces

Question 1

What is Newton’s first law of motions?

Answer 1

Objects will remain at rest, or move with a constant velocity unless acted on by a resultant force

Question 2

What is Newton’s second law (as an equation)?

Answer 2

F = ma (Force = mass x acceleration)

Question 3

What is Hooke’s law (as an equation)?

Answer 3

F = kx (Force = spring constant x extension)

Question 4

What happens if a spring is stretched past the elastic limit?

Answer 4

It no longer obeys Hooke’s law

Question 5

Can the velocity of an object moving in a circular motion be constant?

Answer 5

No - its speed may be constant but since its direction is constantly changing its velocity (a vector) cannot be

Question 6

What factors affect the force needed to make an object follow a circular path?

Answer 6

• Mass (greater –> needs more force)
• Speed (greater –> needs more force)
• Radius of circle (smaller –> needs more force)