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nataly862011 [7]
2 years ago
12

A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft tall walks away from the pole with a speed of 7 ft/s along

a straight path. How fast is the tip of his shadow moving when he is 30 ft from the pole?

Mathematics
2 answers:
saul85 [17]2 years ago
7 0

Answer:

Since only his speed affects how fast his shadow moves, then we calculate for the speed which is 11.67ft/s

Step-by-step explanation:

Assuming similar triangle

(y-x)/y = 6/15

15(y-x) = 6y

15y - 15x = 6y

(15 -6)y = 15x

9y = 15x

y = (5/3)x

By differentiating both sides with respect to time t

dy/dt = 5/3 (dx/dt)

But (dx/dt) is 7 ft/s

Therefore dy/dt = 5/3 * 7 = 35/3 = 11.67ft/s

djverab [1.8K]2 years ago
6 0

Answer:

Step-by-step explanation:

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Step-by-step explanation:

We are given that of the 50 subjects who participate in the study, 16 prefer the instant coffee.

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<em />

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Since, in the question we are not given with the level of significance so we assume it to be 5%. Now, at 5% significance level the z table gives critical values of 1.645 for right-tailed test.

<em>Since our test statistics is more than the critical value of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which </em><u><em>we reject our null hypothesis</em></u><em>.</em>

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