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Gwar [14]
2 years ago
14

Which of the following best demonstrates the effect of static friction? A. A person dropping a ball to the ground. B. A person p

ushing a couch and it slowly sliding across a floor C. A person pushing a couch without being able to move it D. A person moving a ball through a stream of water
Physics
1 answer:
Dominik [7]2 years ago
6 0

Answer:

C.

Explanation:

A person pushing a couch will face resistive force of friction . When resistive force is greater then his force of effort , couch will not move. This force is static friction because the couch is stationary. When the force of effort is increased , magnitude of static friction also increases keeping the couch stationary. The ability of the static friction to increase its magnitude is limited by a maximum value beyond which the couch starts moving. The static friction is then converted into kinetic friction.

In rest of the three cases object is already moving so kinetic friction is in action.

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Answer:

Explanation:

We shall take the help of vector form of displacement . Taking east as i and north as j

4.0m N = 4 j

7.5 m E = 7.5 i

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3.6 m S = - 3.6 j

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5.6 m W = - 5.6 i

4.4 m S = - 4.4 j

4.9 m W = -  4.9 i

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magnitude of displacement = \sqrt{(4.6^2+7.1^2)}

= 8.46 m

Direction

Tanθ = 7.1/ 4.6

θ = 57⁰ south of west .

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= 49.5 m

6 0
3 years ago
Read 2 more answers
A. A light wave moves through glass (n=1.5) at an angle of 25°. What angle will it have when it moves from the glass into air (n
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PART A)

By Snell's law we know that

n_1sin i = n_2 sin r

here we know that

n_1 = 1.5

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n_2 = 1

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Here as we can see that image formed on the other side of lens

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As per the mirror formula we know that

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3 years ago
When a 70 kg man sits on the stool, by what percent does the length of the legs decrease? Assume, for simplicity, that the stool
allochka39001 [22]

The diameter of one leg of the stool is missing and it's 2cm.

Answer:

(ΔL/L) = 0.00729%

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