Biomechanics

Question 1

Newton’s first law

Answer 1

a body continues in a state of rest or uniform velocity unless acted upon by external or unbalanced force.

Question 2

Newton’s second law

Answer 2

A body’s rate of change of momentum is proportional to the size of the force applied and acts in the same direction as the force applied.

Question 3

Newton’s third law

Answer 3

for every action there is an equal and opposite reaction

Question 4

Net force

Answer 4

sum of all forces acting on a body

Question 5

Weight

Answer 5

the gravitational pull that the earth exerts on a body

Question 6

Reaction

Answer 6

the equal and opposite force exerted by a body in response to the action force placed upon it

Question 7

Friction

Answer 7

the force that opposes the motion of two surfaces in contact

Question 8

Centre of mass

Answer 8

the point at which an object or a body is balanced in all directions; the point at which weight appears to act

Question 9

Stability

Answer 9

the ability of a body to resist motion and remain at rest, and the ability to withstand a force applied and return to its original position without damage.

Question 10

Fulcrum location

Answer 10

joint

Question 11

Effort location

Answer 11

muscular force

Question 12

Load location

Answer 12

weight or resistance

Question 13

1st class lever

Answer 13

fulcrum is in the middle

Question 14

2nd class lever

Answer 14

load is in the middle

Question 15

3rd class lever

Answer 15

effort is in the middle

Question 16

Mechanical advantage

Answer 16

2nd class levers where the effort arm is greater than the load arm, a large load can be moved with relatively small effort

Question 17

Mechanical disadvantage

Answer 17

3rd class levers where the load arm is greater than the effort arm, a larger load s required to move a relatively small load