Biomekanik dlm badminton
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ONG KONG SWEE
Bio – benda hidup atau sistem biologi
Mekanik – analisis daya dan kesannya
“Analisis kesan daya dalam kajian aspek anatomi dan fungsi sistem benda hidup”
“Aplikasi prinsip-prinsip mekanik dalam kajian benda hidup”
Bola dipukul oleh raket
Arah pergerakan bergantung kepada daya hasilan akhir daripada semua daya yang bertindak
or uniform motion unless acted upon by
an external force.
If an unbalanced force acts on an object, it will accelerate in the direction of the unbalanced force.
If an object is given a certain initial velocity and there are no unbalanced forces acting on it, the object will continue along its original path in a straight line.Newton’s First Law
object is accelerated by an amount
directly proportional to the force
applied and inversely proportional
to the mass of the object (F = ma).
The greater the force being exerted on an object, the faster the object moves.
The greater the mass of the object, the
slower the object will move in relation to a
lighter object with the same force applied.
A big mass (tennis ball) is harder to accelerate than a smaller mass (table tennis ball).Newton’s Second Law
is determined by the mass of the ball
and how hard the player hits it (F = ma).
A batter gets an advantage if he uses Newton’s Second Law before stepping onto the plate.Newton’s Second Law
Q1. A batter swings with 200N of force on
deck circle, with weights attached making the bat twice as heavy as usual. What is the bat’s acceleration:
a) on the on deck circle?
b) at the plate when the weights have been removed?
Q2. A bat has an acceleration of 80m/s2.
What force was applied to the bat?
Q3. A batter at the plate swings with a force
of 100N. What is the bat’s acceleration? How
does this compare to the answer to Q1.b?
A1.a) F = ma b) F = ma
a = F/m a = F/m
a = 200N/4kg a = 200N/2kg
a = 50m/s2 a = 100m/s2
A2. F = ma
F = 2kg x 80m/s2
F = 160N
A3. F = ma The force applied is
a = F/m half that in Q1.b,
a = 100N/2kg therefore, the
a = 50m/s2 acceleration is halved.
and opposite reaction
For every force between two objects there is always an equal but oppositely directed force.
The normal reaction force is
the support force exerted upon
an object which is in contact
with another stable object.Newton’s Third Law
When hitting a baseball, if we call the force on the bat against the ball the action force, what is the reaction force?
Normal reaction force
When a weightlifter pushes against the ground, the ground pushes against the weightlifter with the same force.
When a tennis player hits a ball with their racquet, the tennis ball exerts an equal but opposite force on the player’s racquet.
Can you think of any more examples?Newton’s Third Law
The reaction force is the force exerted by the ball on the bat.