LECTURE #17 - angular kinematics (2)

Question 1

acceleration of a body in angular motion may be resolved into what two components ?

Answer 1

tangential and radia (a.k.a centripetal)

Question 2

what is tangential acceleration ?

Answer 2

• represents the change in linear velocity for a body traveling on a curved path
• directed tangential to curved pathway

Question 3

what is tangential acceleration tangential to ?

Answer 3

to path of motion

Question 4

what must alpha be expressed in ?

Answer 4

rad/s/s

Question 5

what did newton state in “principia” (the book where he first published his laws) ?

Answer 5

a centripetal force is that by which bodies are drawn or impelled, or any way tend, towards point as to a centre

Question 6

“a centripetal force is that by which bodies are drawn or impelled, or any way tend, towards point as to a centre” is essentially saying that …..

Answer 6

an object must be forced to follow a curved path

Question 7

what does a change in direction = ?

Answer 7

a change in velocity

Question 8

what does a change in velocity = ?

Answer 8

acceleration

Question 9

what is required to change direction and keep an object travelling along a curved path ?

Answer 9

acceleration

Question 10

acceleration is required to change direction and keep an object travelling along a curved path, but where does it come from ?

Answer 10

radial centripetal acceleration

Question 11

what does the radial / centripetal acceleration direct toward ?

Answer 11

the centre, along the curved path

Question 12

what does the radial /centripetal acceleration represent ?

Answer 12

change in direction

Question 13

FILL IN THE BLANK

in regards to radial / centripetal acceleration, linear speed of an object traveling a curved path remains ___________

Answer 13

constant

Question 14

TRUE OR FALSE

with radial / centripetal acceleration, direction of object travelling a curved path is never changing

Answer 14

FALSE

with radial / centripetal acceleration, direction of object travelling a curved path is CONSTANTLY CHANGING

Question 15

TRUE OR FALSE

radial acceleration is also perpendicular to path of motion (centre seeking)

Answer 15

TRUE

Question 16

what do changes in direction result in ?

Answer 16

changes in velocity (even if velocity magnitude is constant)

Question 17

TRUE OR FALSE

changes in velocity result in radial acceleration

Answer 17

TRUE

Question 18

TRUE OR FALSE

radial acceleration is caused by ground reaction forces directed toward the centre of the turn

Answer 18

TRUE

Question 19

what is the purpose of a banked turn ?

Answer 19

trying to produce force in order to make a turn

Question 20

Describe how a taller individual with longer limbs may have a biomechanical advantage in kicking a ball for maximal horizontal displacement over a shorter individual :

Answer 20

these biomechanical advantages contribute to the taller individual being able to generate greater force, speed, and momentum, resulting in a more powerful and potentially longer kick of the ball for maximal horizontal displacement.