Question

Item 9 9 of 15 > Galileo attempted to measure the speed of light by measuring the time elapsed between his opening a lantern and his seeing the light return from his assistant's lantern. The experiment is illustrated in the figure(Figure 1). You may want to review (Pages 885 - 889). Part A What distance, d, must separate Galileo and his assistant in order for the human reaction time, At = 0.2 s, to introduce no more than a 11% error in the speed of light? Express your answer using two significant figures. EVO A ? da m Submit Request Answer Provide Feedback Next > Figure < 1 of 1

Galileo attempted to measure the speed of light by measuring the time elapsed between his opening a lantern and his seeing the light return from his assistant's lantern. The experiment is illustrated in the figure(Figure 1). You may want to review (Pages 885 - 889) .

PART A: What distance, d, must separate Galileo and his assistant in order for the human reaction time, Δt = 0.2 s, to introduce no more than a 11 % error in the speed of light?

With steps please, thanks.

Answer 1

Time, t = 2d/c ...... (1)

(1 - 0.11)c = 2d/(t + dt)

0.89c = 2d/(t + dt)

From equation (1),

0.89c = 2d/[(2d/c) + dt]

2d + c dt = 2dc/0.89c

d = - c dt/[2(1 - 1/0.88)]

d = - (3 x 10^8 x 0.2)/(-0.27)

d = 2.2 x 10^8 m

Comment in case any doubt please rate my answer.....