I. v = +2.0 m/s, Δt = 2.0 s

           II. v = +3.0 m/s, Δt = 2.0 s

           III. v = -3.0 m/s, Δt = 2.0 s

       Which option ranks the displacement of there objects in decreasing order?

a. I, II, III

b. II, III, I

c. II, I, III

d. III, II, I

 

11. Which of these defines acceleration? Choose the correct answer.

a. the change in velocity

b. the change in displacement

c. change of velocity over time

d. the rate of change of displacement

 

12. An object moves at a constant speed in the direction of the arrow.

Which of these describes the object's movement? Choose the correct answer.

a. positive velocity

b. negative velocity

c. positive acceleration

d. negative acceleration

�

An object moves with constant acceleration 4.00 m/s² and over a time interval reaches a final velocity of 12.0 m/s. (a) If its original velocity is 6.00m/s, what is its displacement during the time interval? (b) What is the distance it travels during this interval? (c) If its original velocity is −6.00 m/s, what is its displacement during this interval? (d) What is the total distance it travels during the interval in part (c)?

1. An object moves clockwise with decreasing speed around an oval track. The velocity vectors at points G and H arc shown.

a. In the space at right, copy the velocity vectors  and  . From these vectors, determine the change in velocity vector .

b. If point H were chosen to lie closer to point G, describe how  would change (direction and magnitude).

c. Describe how you would determine the acceleration (direction and magnitude) at point

G. In the space at right, indicate the direction of the acceleration of the object at point G.

d. Copy  and  (placed "tail-to-tail") in the space at right. How does the angle between the acceleration and velocity vectors compare to 900? (i.e., Is the angle greater than, less than, or equal to 90°?)

e.

Generalize your results above and from tutorial to answer the following question:

For an object moving along a curved trajectory, how does the angle between the acceleration and velocity vectors compare to 90° if the object moves with (i) constant speed, (ii) increasing speed, and (iii) decreasing speed?

A particle moves in the xy plane with constant acceleration. Attime zero, the particle is at x = 10.0 m, y = 4.0 m, and hasvelocity v = 2.0 m/s + -4.0 m/s . The acceleration is given by thevector a = 8.0 m/s2 + 8 m/s2 .

(a) Find the velocity vector at t = 7.0 s.

( m/s)i + ( m/s) j

(b) Find the position vector at t = 1.0 s.

( m)i + ( m)j

(c) Give the magnitude and direction of the position vector in part(b).

m

° (counterclockwise from the +x-axis)