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A pencil is rolled off a table of height 0.92 m. If it has horizontal speed pf 1.4 m/s, how long does it take the pencil to reach the ground?

2 Answers

6 votes

Answer:

the real correct answer is 0.43

Step-by-step explanation:

A pencil is rolled off a table of height 0.92 m. If it has horizontal speed pf 1.4 m-example-1
User Jeanel
by
8.1k points
7 votes

The distance an object falls, from rest, in gravity is

D = (1/2) (G) (T²)

'T' is the number seconds it falls.

In this problem,

0.92 meter = (1/2) (9.8) (T²)

Divide each side by 4.9 : 0.92 / 4.9 = T²

Take the square root
of each side: √(0.92/4.9) = T

0.433 sec = T

The horizontal speed doesn't make a bit of difference in
how long it takes to reach the floor. BUT ... if you want to
know how far from the table the pencil lands, you can find
that with the horizontal speed.

The pencil is in the air for 0.433 second.
In that time, it travels
(0.433s) x (1.4 m/s) = 0.606 meter

from the edge of the table.

User Ccampo
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8.0k points