Question

A particle moves along the x-axis from x = 0 to x = 5m under the influence of a force given by
F=7-2x+3x². The work done in the process (in J) is:
(B) 270
(C) 35
(D) 135
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Answer 1

Answer:

We know

$w = \int \: f.dx \\ \\w = \int(7 - 2x + 3 {x}^{2} )dx \\ \\ w = 7x - {x}^{2} + {x}^{3} + c$

Put limits 0 to 5

$w = 7(5) - {5}^{2} + 3( {5}^{3} ) - 0 \\ \implies \\ w = 385 \: j$

Answer 2

Answer:

→ (D) 135

Explanation:

The work done in the process (in J) = ∫ ( 7-2x+3x² ) = 7x - x² + x³

= 7*5 - 5² + 5³ = 135 j

→ (D) 135