chapter 3/4

Question 1

first law

Answer 1

an object will remain at rest or a constant state of uniform motion unless acted upon by a resultant force

Question 2

second law

Answer 2

for a body of constant mass, the force applied is directly proportional to its acceleration

Question 3

third law

Answer 3

when two bodies interact, the forces they exert on each other are equal in magnitude and opposite in direction

Question 4

force

Answer 4

mass times acceleration

Question 5

inertia

Answer 5

ability to resist any change in motion

Question 6

mass

Answer 6

measure of its inertia

Question 7

weight

Answer 7

a force due to gravity

Question 8

centre of gravity

Answer 8

the point at which the force due to weight of an object is considered to act

Question 9

moment

Answer 9

force times perpendicular distance to a pivot

Question 10

torque of a couple

Answer 10

one of the forces of a couple times the perpendicular distance between the forces

Question 11

couple

Answer 11

a pair of forces that are equal in magnitude and opposite in direction

Question 12

conditions for equilibrium

Answer 12

1) summation of the forces in any direction is 0
2) summation of clockwise moments = the summation of anti-clockwise moments