Deck 10: Terminology and Measurement in Biomechanics

Question 1

Which of the following would represent the description of a vector in a polar coordinate system?

A) x = 35, y = 60
B) R = 42, q = 35 ^$\circ$
C) P1 = (2, 6); P2 = (5, 10)
D) none of the above

Answer 1

R = 42, q = 35 ^$\circ$

Question 2

What is the resultant displacement if a hiker walks 250 m north, turns and walks 300 m east?

A) 390.5 m at 40 ^$\circ$
B) 390.5 m at 50 ^$\circ$
C) 550 m at 40 ^$\circ$
D) 550 m at 50 ^$\circ$

Answer 2

390.5 m at 40 ^$\circ$

Question 3

Which of the following represents a scalar quantity?

A) a muscle force of 10 Newtons
B) a displacement of 5 feet
C) a mass of 70 kilograms
D) a velocity of 30 m/s

Answer 3

a mass of 70 kilograms

Question 4

A ball is thrown at an angle of 60 ^$\circ$ with a velocity of 25 m/s. How much of this velocity is vertical (y) and how much is horizontal (x)?

A) x = 12.5 m/s; y = 13 m/s
B) x = 21.65 m/s; y = 12.5 m/s
C) x = 12.5 m/s; y = 21.65 m/s
D) x = 8.3 m/s; y = 16.7 m/s

Question 5

A football blocker tackles an opponent at an angle of 45 ^$\circ$ to the horizontal. How do the horizontal and vertical components of force compare?

A) greater horizontal than vertical component
B) greater vertical than horizontal component
C) both are equal
D) none of the above

Question 6

Name at least three vector quantities that are important in each of the following activities: soccer getting a box out of a cupboard walking

Question 7

You walk north across campus for 200 meters, then turn and walk west for 150 meters. What is your resultant displacement?

Question 8

A runner pushes off of the ground with a force of 500 N at an angle of 30 ^$\circ$ . How much of this force is directed vertically?
How much is horizontal?

Question 9

What may the study of batting in softball be classified as?

A) dynamics
B) kinematics
C) mechanics
D) all of the above

Question 10

Which of the following is not a part of kinematics?

A) displacement
B) velocity
C) acceleration
D) force producing motion

Question 11

A muscle pulls on a bone with a rotary (vertical) force of 25 N. The muscle angle of pull is 15 ^$\circ$ . What is the stabilizing (horizontal) component of this pull?
What is the total resultant muscle force exerted?

Question 12

In which of the following would vectors quantities be found?

A) the standing posture
B) volleyball serve
C) driving a car
D) all of the above
Short Answer Questions

Question 13

What is the primary element in a kinetic analysis?

A) acceleration
B) cause of motion
C) displacement
D) velocity

Question 14

The weight of a body is defined as a quantification of the force of gravity acting on which aspect of the body?

A) resistance
B) weight
C) mass
D) inertia

Question 15

If a muscle pulls on a bone with a force of 300 N at an angle of 30 ^$\circ$ , how much of this force is acting perpendicular to the bone?

A) 260 N
B) 150 N
C) 200 N
D) 100 N

Question 16

Two muscles are attached to bone at the same point. Muscle A is pulling with 90 N of force at an angle of 25 ^$\circ$ . Muscle B pulls with 110 N of force at an angle of 10 ^$\circ$ . What is the combined effect of these two muscles in terms of resultant force and angle of pull?

Question 17

Which of the following represents a vector quantity?

A) a distance of 30 meters
B) a speed of 25 m/s
C) a velocity of 15 m/s
D) a mass of 100 kilograms

Question 18

Which of the following may be assumed if the angle at which a vector quantity is applied is less than 45 ^$\circ$ ?

A) the x component is greater than the y component
B) the y component is greater than the x component
C) the x and y components are equal in magnitude
D) the resultant is less than either component

Question 19

How is the resultant portrayed in the graphic representation of vectors?

A) the vertical side of a rectangle
B) the horizontal side of a rectangle
C) the diagonal of a rectangle
D) the area of a rectangle

Question 20

Which of the following characterizes a vector resultant?

A) larger than either component
B) usually 90 degrees
C) a velocity
D) the adjacent leg in a right triangle