[GenPhys1] Periodical Exam Reviewer

The sum of two vectors has the greatest magnitude when the angle between these two vectors is

• 90º

• 180º

• 270º

• 60º

• None of the Above

Answer explanation

Correct Answer: 0º

Statement 1: Scalar quantities that are fully described by a magnitude (or numerical value) alone.

Statement 2: Examples of vectors include displacement, velocity, weight, acceleration, energy, momentum, and friction.

• Both Statements are TRUE

• Both Statements are FALSE

• Statement 1 is TRUE

  Statement 2 is FALSE

• Statement 1 is FALSE

  Statement 2 is TRUE

Answer explanation

Energy is NOT a vector quantity.

Statement 1: Given a vector whose direction measures 30º East of North, the vector can also be described as having a direction of 30º with respect to the positive x-axis.

Statement 2: The resultant velocity of a train that travels the following three paths - (A) 12 m/s, South (B) 8.0 m/s East (C) 5 m/s North - is 10.6 m/s

• Both Statements are TRUE

• Both Statements are FALSE

• Statement 1 is TRUE

  Statement 2 is FALSE

• Statement 1 is FALSE

  Statement 2 is TRUE

Answer explanation

Statement 1: 60º with respect to the positive x-axis

Statement 2: 11 m/s (Be careful with the significant figures)

You walk 53 m to the north, then turn 60°to your right and walk another 45 m. Determine the direction of your displacement vector. Express your answer as an angle relative to east.

• 50º E of N

• 57º E of N

• 63º E of N

• 67° E of N

• None of the Above

Answer explanation

Correct Answer: 63º N of E

"relative to east"

Find the magnitude of vector v, with its initial point at (-2, 3) and its terminal point at (6, 0). Write your answer in three significant figures.

(NOTE: No units are required)

Find the dot product of the given vectors.

Find the magnitude of the given cross-product. Use three significant figures.

Which of the following is impossible?

• An object has velocity directed east and acceleration directed west.

• An object has velocity directed east and acceleration directed east.

• An object has zero velocity but non-zero acceleration.

• An object has constant non-zero acceleration and changing velocity.

• An object has constant non-zero velocity and changing acceleration.

Under what condition is average velocity equal to the average of the object's initial and final velocity?

• Zero acceleration
• Constant acceleration

• Increasing acceleration

• Decreasing acceleration

• None of the Above

You drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. Your average speed over the 12 km drive will be __ km/h.