Question

Certain force acting on a 20 kg mass churlyc its velocity from 5 m/s to 2 m/s. calculate the work done.​

Answer 1

Correct Question:

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Certain force acting on a 20 kg mass changes its velocity from 5 m/s to 2 m/s. calculate the work done.

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Answer:

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The word done is – 210J.

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Explanation:

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Given:

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• Mass = 20 kg
• Initial velocity (u) = 5 m/s
• Final velocity (v) = 2 m/s

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To find:

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Work done.

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Solution:

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We need to find the work done. So, as we know that

W = F × s

We will use this formula to find the work done.

W = ma (v$^{2}$ – u$^{2}$)/2a

Now by substituting the values, we get

W = 20 × a × (2$^{2}$ – 4$^{2}$)/2a

$\longrightarrow$W = 20 (4 – 25)/2 = 10 × (–21)

$\longrightarrow$ W = – 210 J

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Thus, work done is – 210 J.

Answer 2

Answer:

Here is the answer make

Explanation:

Given :        

Initial velocity (u) = 5ms^-1

Final velocity (v) = 2 ms^-1

Formula:

W = 1/2mv²- 1/2mu²

    =  1/2×20×2²- 1/2×20×5²

    =  10 × 4 - 10 × 25

    = 40 -250

    = -210 J

$Hence the required answer is,\\W = -210 JOULES$

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