chapter 5

Question 1

force

Answer 1

a lush or pulling action applied to an object

Force = Mass X Distance

Question 2

inertia

Answer 2

the resistance of an object to any change in its state of motion

Question 3

newton’s first law of motion

Answer 3

an object in motion stays in motion at the same speed and in the same direction, and an object at rest stays at rest unless acted upon by an external force

Question 4

newton’s second law of motion

Answer 4

an object will accelerate when acted upon by an external force. the acceleration of the object is proportional to this force and is in the direction which the force acts

Question 5

newton’s third law of motion

Answer 5

for every action there exists an opposite and equal reaction

Question 6

gravity

Answer 6

the force that affects a body towards the centre of the earth, or towards any other physical body of mass

Question 7

muscular force

Answer 7

a push or pull applied to an object provided by muscular contraction

Question 8

air resistance

Answer 8

the frictional force that air applies against a moving object

Question 9

ground reaction force

Answer 9

the reaction to the force that the body exerts in the ground

Question 10

lever

Answer 10

a solid bar that turns around an axis to create movement and contains three main components: fulcrum, resistance and effort

Question 11

fulcrum

Answer 11

a fixed point about which the lever can turn; sometimes referred to as the axis

Question 12

resistance

Answer 12

the load or weight that the lever must move

Question 13

effort

Answer 13

the amount of force required to move the load

Question 14

1st class lever

Answer 14

effort top left, fulcrum bottom centre, load top right

Question 15

2nd class lever

Answer 15

effort bottom left, load top centre, fulcrum bottom right

Question 16

3rd class lever

Answer 16

fulcrum bottom left, effort bottom middle, load top right