ROTATIONAL MOTION

What is the direction of the angular velocity vector for a body rotating counterclockwise about the z-axis?

• Along the negative z-axis
• In the xy-plane
• Along the positive z-axis
• Radially outward

What is the significance of the scalar product result being negative?

• Vectors are parallel
• Vectors are perpendicular
• The angle between vectors is obtuse
• One vector is zero

What is the general formula for the cross product of two vectors a and b in component form?

• (a_x b_x)î + (a_y b_y)ĵ + (a_z b_z)k̂
• (a_y b_z - a_z b_y)î + (a_z b_x - a_x b_z)ĵ + (a_x b_y - a_y b_x)k̂
• a_x b_x + a_y b_y + a_z b_z
• (a_x + b_x)î + (a_y + b_y)ĵ + (a_z + b_z)k̂

What is the angle between the unit vectors î and ĵ?

• 0 degrees
• 45 degrees
• 90 degrees
• 180 degrees

What is the result of î × k̂ according to the anti-commutation rule?

• ĵ
• -ĵ
• k̂
• -k̂