ROTATIONAL MOTION

Why is the vector ω × CP directed along the tangent at point P?

• Because it opposes motion
• Because it is radial
• Because it is parallel to ω
• Because it is perpendicular to both ω and CP

What happens to the cross product ω × OC when ω and OC are parallel?

• It equals ω × r
• It becomes infinite
• It becomes ω · OC
• It becomes zero

What is the primary reason for using r⊥ instead of r in rotational velocity calculations?

• r is always zero
• r⊥ is easier to measure
• It represents the effective radius perpendicular to the axis of rotation
• r⊥ includes mass factor

Which of the following best defines rotational motion?

• Motion in a straight line
• Vibration about a mean position
• Free fall under gravity
• Motion of a body about a fixed axis

What is the condition for zero torque due to a force?

• Force is perpendicular to r
• Force is large
• Force is small
• Force is parallel or antiparallel to position vector