Question

calculate the linear (tangential) velocity and centripedal acceleration of a ball kicked at the end of hip flexion. Use hip flexion velocity and leg length as radius for both participant. Compare the two.

Data Collected:

Joint Motion	Participant 1			Participant 2
	Range of motion (degrees)	Limb length (m)	Time (s) for 10 mvmts	Range of motion (degrees)	Limb length (m)	Time (s) for 10 mvmts
Shoulder abduction	165 (goniometer) 171.0 (Dartfish)	.68m	0.3	160 (goniometer) 163.3 (Dartfish)	.86m	0.72
Straight leg flexion	90 (goniometer) 98.7 (Dartish)	.85m	0.52	95 (goniometer) 110.8 (Dartfish)	1.04m	0.82

Angular Velocity (Calculate using time for 1 full movement):

Joint Motion	Participant 1 (degrees/sec)	Participant 1 (radians/sec)	Participant 2 (degrees/sec)	Participant 2 (radians/sec)
Shoulder Abduction/Adduction	550 degrees/sec (goniometer) 570 degrees/sec (Dartfish)	9.6 rad/ sec (goniometer) 9.93 rad/sec (Dartfish)	222.2 degrees/sec (goniometer) 226.8 degrees/sec (Dartfish)	3.88 rad/sec (goniometer) 3.96 rad/sec (Dartfish)
Straight Leg Flexion/Extension	173.1 degrees/ sec (goniometer) 189.8 degrees/sec (Dartfish)	3.02 rad/ sec (goniometer) 3.31 rad/sec (Dartfish)	115.9 degree/sec (goniometer) 135.12 degree/sec (Dartfish)	2.02 rad/sec (goniometer) 2.36 rad/sec (Dartfish)

Answer 1

form participant one

goniometer reading
tangential speed = w*r = 3.02*0.85 = 2.567 m/s
centripital aceleration = w^2*r = 3.02^2*0.85 = 7.75234 m/s/s

Dartfish reading
tangential speed = 3.31*0.85 = 2.8135 m/s
centripital acceleration = w^2*r = 9.312685 m/s/s

for participant 2

goniometer reading
tangential speed = w*r = 2.02*1.04 =2.1008 m/s
centripital aceleration = w^2*r = 2.02^2*1.04= 4.243616 m/s/s

Dartfish reading
tangential speed = 2.36*1.04 =2.4544 m/s
centripital acceleration = w^2*r = 5.792384 m/s/s