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Leya [2.2K]
3 years ago
14

A 20 ft ladder leans against a wall. The bottom of the ladder is 3 ft from the wall at time t=0 and slides away from the wall at

a rate of 2ft/sec. Find the velocity of the top of the ladder at time t=1.
Physics
1 answer:
stellarik [79]3 years ago
5 0

Answer: 0.516 ft/s

Explanation:

Given

Length of ladder L=20 ft

The speed at which the ladder moving away is v=2 ft/s

after 1 sec, the ladder is 5 ft away from the wall

So, the other end of the ladder is at

\Rightarrow y=\sqrt{20^2-5^2}=19.36\ ft

Also, at any instant t

\Rightarrow l^2=x^2+y^2

differentiate w.r.t.

\Rightarrow 0=2xv+2yv_y\\\\\Rightarrow v_y=-\dfrac{x}{y}\times v\\\\\Rightarrow v_y=-\dfrac{5}{19.36}\times 2=0.516\ ft/s

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Answer:

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weight of the water, W_w = M_a - 0.012

The relative density of the oil is given as;

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Therefore, the mass of the body is 0.02 kg.

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