Biomechanics Review Worksheet PDF

1 Biomechanics Review Worksheet 1. Name and briefly explain Newton’s 3 laws of motion. 2. What three variables affect static friction? 3. What magnitude of force would have to be applied to move a wooden box with a mass of 150 kg sitting on a carpeted floor (µ...

1 Biomechanics Review Worksheet 1. Name and briefly explain Newton’s 3 laws of motion. 2. What three variables affect static friction? 3. What magnitude of force would have to be applied to move a wooden box with a mass of 150 kg sitting on a carpeted floor (µs =.65)? 4. Explain the concept, Conservation of Momentum 5. A hockey puck, mass 0.115kg, moving at 35m/s strikes a stationary rubber octopus thrown on the ice by a fan. The octopus has a mass of 0.265kg. The puck and octopus slide off together. What is their velocity? 6. What effect will increasing the time over which a force is applied have on the acceleration of a body? Explain using the relevant formula. 7. A ball with a coefficient of restitution value of.84 (on hardwood) is dropped from a height of 1.5 meters onto a hardwood floor; what height will it rebound to?  2 8. In the biomechanical analysis of a skill, measuring the angle formed between the lower leg and the thigh is a angle. 9. Explain the difference between angular distance and angular displacement 10. A radian is a measure of what quality? a. The number of radians is determined by the ratio of the to the _. 11. Calculate the angular velocity of twirling baton that undergoes one complete revolution in 0.35 seconds; give your answer in rads/sec. 12. What happens to the linear distance travelled by a point on a rotating body as it moves further away from the axis of rotation? What about the angular distance? 13. Assuming no energy lost at impact, what is the resultant velocity of a baseball struck by a bat o with an instantaneous angular velocity (at impact) of 1150 /sec, if the radius of rotation is 1.8 m? 14. If all other factors are held constant, what effect would “choking up” on a bat have on the resultant linear velocity of a hit ball? What does this mean, practically speaking? Explain why in terms of a. Angular Kinematics b. Angular Kinetics 15. What is torque? _________________________________________________ What are the units for torque?_________________  3 16. List the types of levers and explain the distinction between each. 17. A 60 kg diver is positioned so that his radius of gyration is 0.5 m as he leaves the board with an angular velocity of 4 rad/s. What is the diver’s angular velocity when he assumes a tuck position, altering his radius of gyration to 0.25 m? 18. Name three forces that affect the motion of a body through fluids. 19. What is Laminar flow and what is its role in the motion of body through a fluid? 20. Besides propelling her forward, explain precisely why a swimmer needs to kick her legs when trying to move through the water effectively? 21. What does Bernoulli’s principle attempt to explain? Draw a FBD that depicts this principle.  4 Formulae Angular Kinematics θ = angle, ω = angular velocity, vT = tangential velocity d (arc length) = θr ω = θ/t vT = ω x r Angular acceleration α = (ωf – ωi)/t Tangential acceleration at = αr Linear Kinetics 2 N(ewton) = kg m/s Static friction - µs = ≤ fs/Fn Kinetic friction - µk = ≤ fk/Fn Momentum (mass velocity) m1v1 (before) + m2v2 (before) = m1v1 (after) + m2v2 (after) Impulse - Ft = mvf – mvi Elasticity – e = separation speed/approach speed e =√(hb/hd) (sqr rt of bounce height/drop height) Pressure - P = Force/area Angular Kinetics Torque - T = F x d Levers - FA x F = RA x R and MA = FA/RA 2 Angular Inertia (Ia) - Ia = mk Angular momentum (H) - H = Ia x ω, or 2 H = mk 