Unit 2 mechanics Key Terms

Question 1

Newton’s First Law

Answer 1

The motion of an object remains constant or unchanged unless a resultant force acts on it

Question 2

Newton’s 2nd law

Answer 2

Resultant force = mass x acceleration (F = ma)

Acceleration of an object depends on the resultant force that acts on it, and its mass

Question 3

Newton’s 3rd Law

Answer 3

Every action has an equal and opposite reaction

Question 4

Law of conservation of momentum

Answer 4

The total momentum before an interaction is equal to the total momentum after an interaction, in an isolated system

Question 5

Impulse

Answer 5

Total change in momentum

Question 6

Principle of moments

Answer 6

For equilibrium, the vector sum of clockwise moments must equal the vector sum of anticlockwise moments

Question 7

Power

Answer 7

The rate at which energy is transferred

The rate of doing work

Question 8

Elastic Collision

Answer 8

Collision in which kinetic energy isn’t conserved

Question 9

Inelastic Collisions

Answer 9

Collision in which kinetic energy is conserved