Deck 1: Kinematics of Linear Motion

Question 1

What is meant by the term biomechanics?

A) The study of human movement
B) The study of forces and the effects of forces on living things
C) The study of kinematics
D) The study of kinetics
E) The study of how living things effect forces

Answer 1

B
Explanation: E is incorrect. C and D are subjects within biomechanics and biomechanics is an area within A

Question 2

What is meant by the term linear kinematics?

A) Movement along a line that is either straight or curved, where there is no rotation and all body parts move in the same direction at the same speed
B) Movement along a straight line with rotation of body parts
C) Walking or running in a straight line when body parts rotate
D) Movement along a line that is curved, with rotation of body parts
E) Rotational movement of a body around a fixed axis

Answer 2

A
Explanation: Linear (or translatory) kinematics refer to movement in a straight or curved lines as long as there is no rotation and all body parts move in the same direction at the same speed

Question 3

How many yards are there in 1 mile

A) 2.14
B) 1.609
C) 1760
D) 1000
E) 1609

Answer 3

C
Explanation: There are 1,760 yards in 1 mile

Question 4

How many kilometres is 1 mile

A) 1.609
B) 0.621
C) 2.14
D) 1609
E) 1000

Question 5

A scalar quantity is:

A) A quantity that is adjusted to scale
B) A measurement such as velocity
C) A quantity represented by magnitude and direction
D) A quantity represented by magnitude only
E) A quantity represented by direction only

Question 6

Distance is:

A) A vector quantity where direction is needed / known.
B) A scalar quantity where direction is needed / known.
C) A vector quantity that refers to the distance travelled irrespective of direction.
D) A scalar quantity that refers to the distance travelled irrespective of direction.
E) Answers A and C are correct

Question 7

Displacement is:

A) A scalar quantity where direction is needed / known.
B) A vector quantity where direction is needed / known.
C) A vector quantity that refers to the distance travelled irrespective of direction.
D) A scalar quantity that refers to the distance travelled irrespective of direction.
E) Answers A and D are correct

Question 8

Positive acceleration generally means 'speeding up' in in the context of human motion.

Question 9

It is possible to have a 'negative acceleration' value while the athlete or object is actually 'speeding' up.

Question 10

Speed and velocity cannot be measured in the same units because speed does not account for direction.

Question 11

Determine the average speed of an athlete in metres per second (m/s) who ran a 100m race in 10.87 seconds

Question 12

Determine the average speed of an athlete who ran a 10,000 m race in 26 minutes and 17.53 seconds

Question 13

Convert 37.67 minutes into minutes and seconds

Question 14

Provide some examples of scalar quantities in sport

Question 15

Convert 3 hours 23.6 minutes into seconds

Question 16

Convert 3 hours 23.6 minutes into hours

Question 17

Convert 3 hours 23.6 minutes into minutes

Question 18

If an athlete swam a 1500m race in 14 minutes and 31.02 seconds what would be their average speed in m/s?

Question 19

Explain how the units of m/s² for acceleration are derived

Question 20

The centre of mass (COM) is defined as:

A) The point halfway along an object's vertical length.
B) The point at which the entire weight of an object is assumed to be concentrated.
C) The point that corresponds to the mean (average) position for the concentration of the entire matter in the body or segment.
D) A value that is half of the total mass of an object.
E) Non-existent.

Question 21

The centre of gravity (COG) is defined as:

A) The point that corresponds to the mean (average) position for the concentration of the entire matter in the body.
B) The point halfway along an object's vertical length.
C) A value that is half of the total mass of an object.
D) Non-existent.
E) The point at which the entire weight of an object is assumed to be concentrated.

Question 22

A person is standing upright with their arms by their sides. If they were to move their arms up over their head, their centre of gravity should:

A) Move down towards the ground.
B) Be located at their feet so they don't fall over.
C) Move slightly upwards towards their head.
D) Stay in the same position.
E) Move laterally.

Question 23

The centre of gravity is always located within the body and cannot be located outside of the body.

Question 24

In a regularly-shaped object of uniform density, the centre of gravity is found at the geometric centre of the object.

Question 25

The centre of gravity in the human body may move depending on the posture and position of the limbs.

Question 26

Stability is decreased when the centre of gravity (COG) of the object lies nearer the lower part of the object and when a vertical line through the COG falls within the base of support the object.

Question 27

State two ways the centre of gravity may influence the stability of an object

Question 28

Use the equation 'Moment = force (Mass of limb x acceleration due to gravity) × perpendicular distance from axis of rotation' to calculate the moment about the OX axis for the hand when:
0.006 = the percentage of mass of the whole body for this segment expressed as a decimal (i.e., a proportion of 1.0 or 0.6%)
82 = athlete's mass in kilograms (kg)
9.81 = acceleration due to gravity expressed in m/s²
1.40 = perpendicular distance from OX which is 140 cm to be expressed in meters (m) along Y

Question 29

You have an athlete lying on a centre of gravity board. Use the formula:
x₁ = (W₃ . d)/W₁
to calculate the x₁ (the horizontal distance from the fulcrum to the body centre of gravity) when:
Athlete = 62kg
d = 3.5m
W₃ = 171N

Question 30

Which of the following statements is true regarding 'stability'

A) Stability can be described as the ability of an object to maintain its posture or position.
B) Stability refers to the ability of an object to stretch and return to its original shape.
C) Stability is increased when the center of gravity of an object is further from the ground.
D) Stability is only present when the center of gravity falls outside of the object's base of support.
E) Stability can be described as the inability of an object to stretch without deformation.

Question 31

Static equilibrium is:

A) When the sum of all external forces acting on an object or body is 1 (∑F = 1).
B) When an object or body is moving with a constant velocity (i.e. not accelerating).
C) When an object or body is at rest (i.e. not moving).
D) When the sum of all external forces acting on an object or body is 1 (∑F = -1).
E) When an object or body is accelerating at a constant rate.

Question 32

Dynamic equilibrium is:

A) When an object or body is at rest (i.e. not moving).
B) When the sum of external forces acting on an object or body is 0 (∑F = 0).
C) When an object or body is accelerating at differing rates.
D) When an object or body is moving with a constant velocity (i.e. not accelerating).
E) When an object or body is accelerating at a constant rate.

Question 33

A pair of equal and opposite parallel forces that will often cause rotations of objects about specific axis is called:

A) A parallelogram.
B) A force couple.
C) A couple of forces.
D) An axial force.
E) A linear rotation.

Question 34

If an obect is placed on a table in static equilibrium and exerts a force of - 35N onto the table, the reaction force from the table would be 35N.

Question 35

Resultant forces equal to two co-planar (occupying the same plane) forces acting on an object can only be solved mathematically.

Question 36

The stability of an object can be increased by lowering the center of gravity closer to the ground, increasing the base of support and maintaining the centre of gravity within the base of support. Stability is also increased in objects with greater mass.

Question 37

An athlete is holding a 5kg dumbbell in their hand maintaining an elbow joint angle of approximately 100° of elbow flexion. Rearrange the equation "∑CWM + ∑ACWM = 0" to solve for the muscle force (F₁) needed to maintain static equilibrium, when:
F₂ x d₂ = clockwise moment (negative) (∑CWM)
F₁ x d₁ = anti-clockwise moment (positive) (∑ACWM)
Weight force of arm, hand and dumbbell mass x acceleration due to gravity (F₂) = 9kg x 9.81m/s²
Perpendicular distance from joint axis to muscle force (d₁) = 0.04m
Perpendicular distance from joint axis to weight force (d₂) = 0.36m

Question 38

Draw a free body diagram (using the tip to tail method) to measure the resultant force for the following two forces:
A force of 25N in a North-Easterly direction
A force of 15N in a North-Westerly direction

Question 39

What are the first and second conditions of equilibrium?

Question 40

Which of the following graphs is most likely to represent the acceleration of an athlete during a 100 m sprint?

A) Image a
B) Image b
C) Image c
D) Image d
E) Image e

Question 41

The top graph in the figure below shows position vs time of an athlete performing a shuttle run (i.e. forwards and backwards). Which of the four graphs below this (a - d) is most likely to represent the athlete's velocity vs time for the same movement?

A) Image a
B) Image b
C) Image c
D) Image d

Question 42

Immediately before the body comes to rest at the end of the countermovement of an standing vertical jump, which of the following statements is true?

A) Velocity is negative and speed is decreasing.
B) Velocity is zero.
C) Velocity is positive and speed is increasing.
D) Velocity is positive and speed is decreasing.
E) Velocity is negative and speed is increasing.

Question 43

During which of the following phases of a standing vertical jump is this statement true? 'The jumper's position is increasing, and both their velocity and acceleration are positive'.

A) Between the jumper's first movement and when they reach their peak downwards velocity during the countermovement.
B) Between when they reach their peak downwards velocity during the countermovement and when they reach the bottom of the countermovement.
C) Between the bottom of the countermovement and when they reach their peak upwards velocity before the instant of take off.
D) Between when they reach their peak upwards velocity and the instant of take off.

Question 44

The position of the head of a golf club before ball impact (t = 0.020 s) is summarised in the table below: What is the velocity of the club between 0.016 s & 0.018 s and 0.018 s & 0.020 s, and the acceleration of the club between these velocities?

A) 47.5 m/s, 52.5 m/s and -2500 m/s²
B) 52.5 m/s, 47.5 m/s and 2500 m/s²
C) 52.5 m/s, -47.5 m/s and -2500 m/s²
D) 47.5 m/s, 52.5 m/s and 2500 m/s²
E) 52.5 m/s, 47.5 m/s and -2500 m/s²

Question 45

Figure A4.5

-Considering the knee flexion (top) graph in Figure A4.5, the knee flexes three times

Question 46

Figure A4.5

-Considering Figure A4.5, the knee flexes with it's greatest angular velocity at the start of the stride

Question 47

Figure A4.5

-Considering the knee flexion velocity (middle) graph in Figure A4.5, when the curve crosses through zero for the final time, the knee is transitioning between flexion and extension.

Question 48

How far does the athlete travel at the end of the (hypothetical) velocity - time profile below?

A) 25 m
B) 30 m
C) 35 m
D) 40 m
E) 45 m

Question 49

The table below contains data from the countermovement of a standing vertical jump (i.e. the downward movement at the start of the jump. Use the Trapezium Rule to calculate the change in velocity of the jumper at 0.16, 0.32 and 0.48 s.

A) 0.1064, -0.0312 and 0.15 m/s
B) -0.1064, 0.0312 and 0.15 m/s
C) -0.1064, -0.0312 and -0.15 m/s
D) -0.1064, -0.0312 and 0.15 m/s
E) -0.1064, -0.0312 and -0.15 m/s

Question 50

A volleyball player performs a standing vertical jump with a take off velocity of 2.6 m/s. What is the height raised by their body during flight?

A) 0.34 m
B) 0.69 m
C) 2.6 m
D) Not enough information to answer the question
E) 0.13 m

Question 51

A sprinter has a constant acceleration of 2 m/s² during the first 5 s of a 100 m race. How far do they travel during this time?

A) 5 m
B) 75 m
C) 25 m
D) 10 m
E) 50 m

Question 52

A golf ball is struck with a velocity of 16 m/s at an angle of 56º. What is its range (i.e. horizontal displacement) if it lands at the same height that it was struck from?

A) 51.0 m
B) 35.3 m
C) 24.2 m
D) 28.2 m
E) 17.3 m

Question 53

A pole vaulter takes 1.3 s to fall from peak height to the landing mat. What is their vertical velocity on contact with the mat?

A) -12.7 m/s
B) 11.1 m/s
C) -11.1 m/s
D) Not enough information to answer the question
E) 12.7 m/s

Question 54

Which of the following graphs most closely depicts the relationship between the take off velocity and the range (i.e. horizontal displacement) of a projectile?

A) Image a
B) Image b
C) Image c
D) Image d
E) Image e

Question 55

Which of the following graphs would be most likely to represent the relationship between velocity and the optimal angle of a projectile that is released from a higher position than it lands?

A) Image a
B) Image b
C) Image c
D) Image d
E) Image e