Solve the problem.
-A velocity indicates that the object is traveling upward and a velocity indicates that the object is traveling downward. An object is projected upward and . Determine the interval when the
Object is traveling upward.
A) [0, 3]
B) [0, 32]
C) [4, 10]
D) [0, 4]

Question

Solve the problem.
-A velocity  indicates that the object is traveling upward and a velocity  indicates that the object is traveling downward. An object is projected upward and  . Determine the interval when the
Object is traveling upward.
A) [0, 3] 
B) [0, 32] 
C) [4, 10] 
D) [0, 4]

Quizplus · Accepted Answer

Since the initial velocity is upward, the object is traveling upward until the velocity becomes zero.  
Using the equation of motion, vf = vi + at, we get:

0 = 11ebb63d_1c0a_9d21_b851_350b657d6db3_TB8475_11 - g*t

Solving for t, we get t = 11ebb63d_1c0a_9d21_b851_581165689cd3_TB8475_11 .

Since we are only interested in the interval when the object is traveling upward after it is projected, we can consider the interval [0, t] and check the sign of the velocity. 
v = vi + at 
For upward motion, a = -g and vi is positive, so the velocity is decreasing. So, the interval when the object is traveling upward is [0, t] where t = 11ebb63d_1c0a_9d21_b851_581165689cd3_TB8475_11 . Therefore, the answer is D.

Solve the Problem. -A Velocity Indicates That the Object Is Traveling Upward