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Biomechanics
Student Response Sheet
1.
People often use the words mass and weight interchangeably but they are different. What is the difference between
mass and weight?
2.
(i) What is velocity?
(ii) When discussing velocity, it’s important that two other variables are also considered, what are they?
3.
How can the velocity of an object be changed?
4.
What is inertia?
5.
(EXT) What is the relationship between inertia and mass?
6.
People often use the words acceleration and speed interchangeably but they are different. What is the difference
between acceleration and speed?
7.
(EXT) We known that F = m x a (Force = mass x acceleration)
(i) If the same force is applied to two different objects (different masses); which one will have the greatest
acceleration?
a) A = mass 5 kg
b) B = mass 10 kg
(ii) In this example, if the mass is doubled what effect will this have on acceleration if the same force is applied?
8.
What is momentum and how can this be expressed as a mathematical formula?
9.
(i) What is impulse?
(ii) What is the mathematical formula for impulse?
(iii) (EXT) By using the principle of impulse, why is the discus spin better than simply standing side on and
releasing the discus in terms of furthest distance attainable?
10. (i) Force absorption relates to how long a force is “accepted” for. The longer a force is absorbed, the greater/less
the impulse is. (delete one)
(ii) If a ball is thrown with great force from a short distance away, why is it better to try and “give” with the ball at
point of impact rather than try to catch the ball with “rigid” or locked arms?
11. Newton’s third law of motion stated that for each action, there is an equal and opposite reaction. Provide three
sporting examples to clearly highlight this law which is also known as:
1.
2.
3.
12. (i) What is elasticity?
(ii) Why will a tennis ball bounce more on a “rebound ace” surface such as that found at Rod Laver Arena
(Melbourne) compared to a ball bounced on the grass courts of Wimbledon?
(iii) (EXT) What is the relationship between string tension of a tennis racquet and its elasticity?
13. (i) What is force summation?
(ii) For force summation to be effective in producing maximum speed, momentum needs to move from
____________________body parts to ________________ body parts.
(iii) (EXT) Many sportspeople can move body parts quickly but are not necessarily able to summate this force –
briefly explain why?
(iv) (EXT) In terms of force summation, why is a follow through important after contact or release to bring about
optimal performance?
14. How is accuracy and force summation different?
15. (i) Briefly explain how flattening the arc increases accuracy.
(ii) (EXT) Draw the path of a softball pitch and how the arc is flattened by the pitcher stepping forward prior to
release of the ball.
16. (i) Friction is
(ii) Provide 3 sporting examples of where increased friction is important to successful performance.
(iii) Provide 3 sporting examples of where decreased friction is important to successful performance.
17. All levers have 3 common parts – list these below.
18. There are 3 classes of levers. Draw a diagram to clearly show the three different placements of the force/effort;
axis/fulcrum and resistance/load in each class of lever.
1st Class Lever
2nd Class Lever
3rd Class lever
19. Clearly define:
(i) The force arm
(ii) The resistance arm
(iii) What is the advantage of having a longer force arm than the resistance arm?
(iv) What is the advantage of having a longer resistance arm than force arm?
20. The velocity at the end of a longer lever is greater/less than that at the end of a shorter lever.
(delete one)
21. Much junior sporting equipment is made of lightweight materials such as plastic, fibreglass or aluminium and tends
to be smaller than that used by older people.
(EXT) What effect does this have on the inertia of junior sporting equipment and the overall ability of young people
to use the equipment effectively?
22 (i) What is linear motion?
(ii) Provide 2 sporting examples to highlight linear motion.
23. (i) What is angular motion?
(ii) Provide 2 sporting examples to highlight angular motion.
24. What is general motion?
25. (i) What is torque?
(ii) What is the equation used to calculate torque?
(iii) Why will using a 36 cm baseball bat generate greater torque than a 30 cm baseball bat?
(iv) Which length baseball bat will potentially hit the baseball furthest assuming the same force is applied by the
batter? Briefly discuss why.
26. (i) What is moment of inertia?
(ii) How can this be expressed as a mathematical formula?
27. (i) What is angular momentum?
(ii) How can this be expressed as a mathematical formula?
28. (EXT) Why can bodies rotate quicker when body parts such as the arms and legs are “tucked in” and kept close to
the body, compared to when they are extended away from the body? (Look at the gymnast in the program or think of
an ice-skater spinning quicker or slowing to a stop)
29. (a) When bodies are projected into the air the follow a curved or ______________ flight path. Factors that affect
this flight path (excluding gravity) are:
(i)
(ii)
(iii)
(b) In most sporting situations the optimal height of release to gain maximal distance is 45 degrees.
When would a height of release of 60 degrees be an advantage in a sporting situation? Provide an example.
(c) When would a height of release of 30 degrees be an advantage in a sporting situation? Provide an example.
30. The “Magnus effect” describes how a ball spins through the air.
(i) Briefly describe how pressure differences cause balls to spin through the air.
(ii) What might be responsible for these pressure differences?
31. List at least two factors that effect balance and stability:
(i)
(ii)
(iii) Others:32. The larger the base of support, the greater/less the stability of the object. (delete incorrect)
33. Briefly discuss what happens to stability if the line of gravity falls outside the base of support.
34. Which of the following would have the greatest stability?
(i)
(ii)
(iii)
a 190 cm, 90 kg footballer
a 190cm, 85 kg footballer
a 175 cm, 90 kg footballer
Briefly discuss your selection.