BMC Exam 2 UPDATED Study Guide
QUESTIONS AND CORRECT ANSWERS
Static Equilibrium - CORRECT ANSWERS Object at rest; net force = 0,
net torque = 0
Dynamic Equilibrium - CORRECT ANSWERS Object moving at
constant velocity; no acceleration
Stable Equilibrium - CORRECT ANSWERS Needs a large force/torque
to disturb position
Unstable Equilibrium - CORRECT ANSWERS Small force/torque easily
disturbs equilibrium; used for quick mobility
Impulse - CORRECT ANSWERS Impulse = Force × Time (ΣF Δt =
ΔMomentum)
Examples of Impulse - CORRECT ANSWERS Baseball bat hit, kicking
a ball, jumping push-off, catching a medicine ball
Center of Gravity (COG) - CORRECT ANSWERS Point where torques
balance
Line of Gravity (LOG) - CORRECT ANSWERS Vertical line through
COG
Base of Support (BOS) - CORRECT ANSWERS Area under points of
contact
, Challenge BOS - CORRECT ANSWERS Narrow stance, stand on one
foot, use unstable surface, add movement
External Forces - CORRECT ANSWERS Act from outside (gravity,
ground reaction, friction) → change motion
Internal Forces - CORRECT ANSWERS Act inside system (muscles,
joints) → change shape
Stability - CORRECT ANSWERS Mechanical resistance to disturbance
Balance - CORRECT ANSWERS Neuromuscular control of equilibrium
Stability and Mobility Trade-Off - CORRECT ANSWERS More stability
= less mobility
Gravity - CORRECT ANSWERS Force pulling mass toward Earth
Weight Changes - CORRECT ANSWERS Changes slightly with distance
from Earth's center (less at equator, more at poles)
Assistive Devices and BOS - CORRECT ANSWERS Canes, walkers →
increase BOS size
Torque - CORRECT ANSWERS Torque = Force × Distance from axis
(moment arm)
Linear Displacement - CORRECT ANSWERS Straight-line change in
position (vector)
QUESTIONS AND CORRECT ANSWERS
Static Equilibrium - CORRECT ANSWERS Object at rest; net force = 0,
net torque = 0
Dynamic Equilibrium - CORRECT ANSWERS Object moving at
constant velocity; no acceleration
Stable Equilibrium - CORRECT ANSWERS Needs a large force/torque
to disturb position
Unstable Equilibrium - CORRECT ANSWERS Small force/torque easily
disturbs equilibrium; used for quick mobility
Impulse - CORRECT ANSWERS Impulse = Force × Time (ΣF Δt =
ΔMomentum)
Examples of Impulse - CORRECT ANSWERS Baseball bat hit, kicking
a ball, jumping push-off, catching a medicine ball
Center of Gravity (COG) - CORRECT ANSWERS Point where torques
balance
Line of Gravity (LOG) - CORRECT ANSWERS Vertical line through
COG
Base of Support (BOS) - CORRECT ANSWERS Area under points of
contact
, Challenge BOS - CORRECT ANSWERS Narrow stance, stand on one
foot, use unstable surface, add movement
External Forces - CORRECT ANSWERS Act from outside (gravity,
ground reaction, friction) → change motion
Internal Forces - CORRECT ANSWERS Act inside system (muscles,
joints) → change shape
Stability - CORRECT ANSWERS Mechanical resistance to disturbance
Balance - CORRECT ANSWERS Neuromuscular control of equilibrium
Stability and Mobility Trade-Off - CORRECT ANSWERS More stability
= less mobility
Gravity - CORRECT ANSWERS Force pulling mass toward Earth
Weight Changes - CORRECT ANSWERS Changes slightly with distance
from Earth's center (less at equator, more at poles)
Assistive Devices and BOS - CORRECT ANSWERS Canes, walkers →
increase BOS size
Torque - CORRECT ANSWERS Torque = Force × Distance from axis
(moment arm)
Linear Displacement - CORRECT ANSWERS Straight-line change in
position (vector)
