2. An object is initially at the origin. The object changes its position to the right by 4 units. The object then changes its position to the left by 3 units. Which of the following correctly indicates the magnitude of the object’s change in position and provides a valid justification?

(A) 1 unit, because in one dimension vectors with opposite directions have opposite signs.

(B) 1unit, because the magnitude of the difference of two vectors is always equal to the difference between the magnitudes of the vectors.

(C)7 units, because the magnitude of the sum of two vectors is always equal to the sum of the magnitudes of the vectors.

(D) 7 units, because the object moves a distance of 4 units followed by a distance of 3 units

A B C D

3. A student slides a box across a level floor in a straight, horizontal path as shown in the picture. At time t₁ , the box is moving to the right at 1m/s . At time t₂ , the box is moving to the left at 1m/s . Which of the following correctly describes the speed and velocity at the times t₁ and t₂?

A B C D

4. During time interval t₁, a car starts from rest and speeds up at a constant rate to the right until reaching a final velocity v₁ . Then, during time interval t₂, the car slows down at a constant rate until it comes to rest. Which of the following correctly indicates whether the signs and directions of the car’s acceleration during the two time intervals are the same or different?

A B C D

5. Cars A, B, C, and D are moving along a straight track. The table indicates their velocities and accelerations at the same instant. Which car has the acceleration with the greatest magnitude?

A B C D

6. An object on a straight, horizontal track with an initial positive velocity undergoes a constant acceleration of -5m/s²for 4 seconds. Which of the following is the change in velocity of the object during this interval?
(A) 4m/s^s
(B) 8m/s^s
(C) 20m/s^s
(D) 30m/s^s

A B C D

7. A car is driving east on a straight, level road with a speed of 20m/s when it begins to accelerate eastward at a constant rate. After 5s the car has a speed of 40m/s to the east. The acceleration of the car during the 5s time interval is
(A) 4m/s^s
(B) 8m/s^s
(C) 20m/s^s
(D) 30m/s^s

A B C D

8. A cart is moving along a straight track and has velocity +0.5m/sand positive acceleration at time 1s. At time 3s, the cart reaches a maximum speed. At time 4s , the cart again has velocity +0.5m/s , but with negative acceleration. A student claims that the average acceleration of the cart between time 1sand time 4s is zero. Is the student’s claim correct? Why or why not?

(A) Yes, because the final velocity of the cart is equal to the initial velocity.

(B) Yes, because the cart returns to its original position.

(C) No, because the values of the acceleration at time 1s and time 4s are unknown.

(D) No, because the cart spends more time with a positive acceleration than with a negative acceleration.

A B C D

9.A 1.5kg cart starts from rest and then accelerates at a constant rate of 2m/s²to the right for 5s. The displacement of the cart over this time interval is most nearly

(A) 3m

(B) 10m

(C) 15m

(D) 25m

A B C D