Question 11 pts

A vector that rotates has a derivative with respect to time, even if its length is constant.Group of answer choicesTrue

False

Flag question: Question 2Question 21 pts

The time derivative of a rotating unit vector is obtained by the following CROSS product: angular velocity VECTOR with which the unit vector rotates CROSS with the unit vector itselfGroup of answer choicesTrue

False

Flag question: Question 3Question 31 pts

If position vector is d e_r, with constant d (i.e., constant distance but rotating around the center as e_r changes). Pick the right answer (here x-dot means time derivative of x)Group of answer choicesVelocity is d (e_r-dot)

Speed is zero

Velocity = d theta (theta-dot)

Velocity is zero

Flag question: Question 4Question 41 pts

Suppose the position vector was r= d e_r , where theta is fixed (i.e., e_r does not rotate) but the length d is NOT constant. Which one of the following is correctGroup of answer choicesVelocity is (d-dot) e_r

Velocity = d theta (theta-dot)

Speed is zero

Velocity is zero

Flag question: Question 5Question 51 pts

In Polar coordinates, which one of the following statements is trueGroup of answer choicesIn a constant radius rotation, there is always radial acceleration

In a rotating motion, second derivative of theta is always zero

In a constant radius rotation, there is no tangential acceleration

If motion is in a straight line, there is no acceleration

Flag question: Question 6Question 61 pts

If motion is circular with constant radius, what is the so call `centrifugal acceleration'Group of answer choicesit is the - r (\theta-dot)^2 in e_r direction

it is none of the above

It is the 2 \theta-dor r=dot term

It is the d^2/d t^2 of r term