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5 votes
You toss a marble straight up into the air with a speed of 1.3 m/s. How long does it take the marble to reach its highest point?

A. 0.55 s
B. 2.2 s
C. 7.5 s
D. 0.13 s

2 Answers

5 votes
D
Reason:-
applying the formula
vf=vi+gt
1.3/9.8=t
0.13=t(Ans)
User Youssof
by
7.6k points
4 votes
The acceleration of gravity is 9.8 m/s². That means that the speed of the marble is always 9.8 m/s greater downward than it was 1 second earlier.

You want to know when the marble is going to stop climbing. Well, that
will be when its upward velocity has dwindled to zero. That in turn is the
time when its upward velocity is 1.3 m/s less than it was when you tossed it.

(1.3 m/s) / (9.8 m/s²) = 0.133 second (rounded)
User Kuba
by
8.0k points