Objectives Pecina
y
01:Posttest 01:Motion Along a Straight Line
eration
1. An elevator moving down passes its neighbor, an elevator moving up. Their speed relative to one another is 8 m/s. What is the velocity of each
elevator relative to someone standing on the first floor? Assume that the elevators are traveling at the same speed, and that the upward direction is
positive.
tant Acceleration
O Both elevators are moving at 8 m/s.
y Falling Objects
O One elevator is moving at 4 m/s; the other elevator is moving at -4 m/s.
O Both elevators are moving at 4 m/s.
tive Velocity
O One elevator is moving at 8 m/s; the other elevator is moving at -8 m/s.
Posttest
on in a Plane
ton's Laws of Motion
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blications of Newton's
Description
440
11:53 PM
4/4/2021

B

Explanation:

Given that an elevator moving down passes its neighbor, an elevator moving up. Their speed relative to one another is 8 m/s. What is the velocity of each elevator relative to someone standing on the first floor? Assume that the elevators are traveling at the same speed, and that the upward direction is

positive.

Solution

Given that upward direction is positive, then, the downward direction will be negative.

To get a relative velocity of 8m/s

4 - ( - 4 ) = 8

Therefore, the correct answer will be

One elevator is moving at 4 m/s; the other elevator is moving at -4 m/s

Which is option B

Because the negative multiply by negative sign will give positive sign.

Given

4 + 4 = 8.

any one of the statements could be an accurate comparison. but the statement that would define the correct choice and seal the deal is not even on the list:

"the visibilities of vector-x and vector-y in the drawing provided with the question are identical and nonexistent."