Question

question 3 (3 points) (01.09 mc) two ticker tape results are shown: which statement accurately describes the motion of the objects in the ticker tape above? a both objects are speeding up at a constant rate. b one object speeds up before it slows to a stop. c both objects speed up before stopping. d one object speeds up at a constant rate until it stops.

Explanation:

To determine the motion from ticker tapes, we analyze the dot spacing (time between dots is constant, so spacing relates to speed: wider spacing = higher speed, narrower = lower speed).

• Top tape: Dots start close (low speed), then widen (speed up), then narrow (slow down) until very close (stop).
• Bottom tape: Dots start wide (high speed? No—wait, first dot to second is wide, then spacing decreases (slowing? No, wait—wait, no: initial dots are far apart (high speed), then get closer (slowing down? No, wait, no—wait, the bottom tape: first dot, then a gap, then dot, gap, then dots get closer (so speed decreases? No, wait, no—wait, the top tape: first four dots close (low speed), then a wide gap (speed up), then gaps narrow (slow down) to stop. The bottom tape: first dot, wide gap (speed up), then gaps narrow (slow down) until dots are close (stop)? No, wait, the bottom tape’s dots at the end are close together, meaning low speed, while initial dots are far (high speed). Wait, no—wait, the key is: for the top tape, the dot spacing first increases (speeding up) then decreases (slowing down) until stopping. For the bottom tape, does it speed up or slow down? Wait, no—wait, the options:
• Option a: Both speeding up at constant rate. But top tape slows down, so no.
• Option b: One object speeds up before it slows to a stop. Let’s check: Top tape: starts with close dots (low speed), then wider (speed up), then narrower (slow down) to stop. Bottom tape: starts with wide dots (high speed), then narrower (slow down) to stop? No, wait, maybe I misread. Wait, the top tape: first four dots are close (time between dots is same, so distance between dots is speed × time. So close dots = low speed. Then a wide gap (high speed, speeding up), then dots get closer (slowing down) until very close (stop). So top tape: speeds up then slows to stop. Bottom tape: first dot, wide gap (high speed), then gaps get narrower (slowing down) until dots are close (stop)? No, wait, the bottom tape’s dots at the end are close, so it’s slowing down from high speed? But the option b says “One object speeds up before it slows to a stop.” So top tape speeds up (dots widen) then slows (dots narrow) to stop. Bottom tape: does it speed up? Wait, bottom tape’s first dot, then a wide gap (high speed), then next gap is narrower (slower), so it’s slowing down from high speed, not speeding up. So only the top tape speeds up then slows to stop. So option b: “One object speeds up before it slows to a stop” matches.
• Option c: Both speed up before stopping. Bottom tape doesn’t speed up (starts with wide dots, then narrows), so no.
• Option d: One object speeds up at constant rate until it stops. But top tape slows down, so no.

Answer:

b. One object speeds up before it slows to a stop.