PRE-LAB QUESTIONS 1. A plastic strip has 8 black stripes and 8 clear stripes. Th

Question

PRE-LAB QUESTIONS 1. A plastic strip has 8 black stripes and 8 clear stripes. The width of the black/clear pair is d = 5 cm (0.05 m). The strip is held just above the photogate and released. a) How much time does it take the first black/clear pair to fall through the photogate timer, starting from rest? b) What is the average velocity for the first pair (using the given d, and time from held at 20% to part a)? c) If the strip is held at an angle of 20° from vertical, as shown in Figure 4, what is the vertical distance, y? d) How long does it take the strip to fall a distance y, starting from rest? e) If the computer calculates an average velocity by assuming that the strip was vertical and that the distance was d, not y, what velocity will it calculate for the first pair using the time in part (d)? f) What is the percentage error in velocity due to tilting the strip by 20°? g) Will air resistance decrease or increase the measured acceleration? Figure 4. A strip vertical.

Explanation / Answer

1) d = 0.05 m ;

a)We know that,

s = ut + 1/2 a t^2 ; for u = 0

t = sqrt (2s/a)

s = d and a = g

t = sqrt (2 x 0.05/9.81) = 0.101 s

Hence, t = 0.101 s

b)v = d/t

v = 0.05/0.101 = 0.495 m/s

Hence, v = 0.495 m/s

c)the length of the strip is:

H = 4 x 0.05 = 0.2 m

from trigonometry

L/H = cos(theta)

L = H cos(theta)

L = 0.2 x cos20 = 0.188 m

Hence, L = 0.188 m

d)again using the same relation, but now s = 0.188

t = sqrt (2 x 0.188/9.81) = 0.196 s

Hence, t = 0.196 s

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.