9. [1pt] 10 -10 1 2 3 Time sec) 4 5 The graph shows the upward speed of a ball t
ID: 1789581 • Letter: 9
Question
9. [1pt] 10 -10 1 2 3 Time sec) 4 5 The graph shows the upward speed of a ball thrown up with an initial speed of 27.0 m/s from the surface of Venus. Select whether an answer is True or False (for example, if only B is True, enter FTFFFF). 3.1s. A) The velocity vector and the acceleration vector are in the same direction after t B) The acceleration is 0 near t-3.1s. C) Maximum height is reached at about t-3.1s. D) The ball's KE increases during the first second. E) The ball's PE is a constant. F) The acceleration is constant.Explanation / Answer
A.True
since after t=3.1 s ,the velocity vector is in downward direction and acceleration is also in downward direction.
B.False
since acceleration due to gravity is constant a=-9.8 m/s2
C.
True
at Maximum height ,the final velocity is zero ,from figure at t=3.1 s ,the velocity is zero.
d.
False
since speed decreases every second during upward motion
e.
False
since it chages with height
f.
True
Here acceleration is acceleration due to gravity