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QJEEM23Ph19cb: JEE Main 2023 Physics - Class 11 JEEM23Ph19cb Solution: A force acts on a particle in the direction where F is in…

A force F⃗=(2+3x)i^\vec{F}=(2+3 x) \hat{i} acts on a particle in the xx direction where F is in newton and xx is in meter. The work done by this force during a displacement from x=0x=0 to x=4 mx=4 \mathrm{~m} , is __________ J.

Step-by-Step Verified Solution

To find the work done by a force during a displacement, we can use the formula:

W=∫x1x2F⃗⋅dx⃗W = \int_{x_1}^{x_2} \vec{F} \cdot d\vec{x}

Here, the force is given by F⃗=(2+3x)i^\vec{F} = (2+3x) \hat{i} , and we need to find the work done during a displacement from x=0x = 0 to x=4 mx = 4 \mathrm{~m} . Since the force is only in the xx direction, we can write the integral as:

W=∫04(2+3x)dxW = \int_{0}^{4} (2+3x) dx

Now we can integrate the function with respect to xx :

W=∫04(2+3x)dx=∫042dx+∫043xdxW = \int_{0}^{4} (2+3x) dx = \int_{0}^{4} 2 dx + \int_{0}^{4} 3x dx

W=[2x]04+[32x2]04W = \left[ 2x \right]_0^4 + \left[ \frac{3}{2}x^2 \right]_0^4

Now we can plug in the limits of integration:

W=(2⋅4−2⋅0)+(32⋅42−32⋅02)W = (2 \cdot 4 - 2 \cdot 0) + \left(\frac{3}{2} \cdot 4^2 - \frac{3}{2} \cdot 0^2 \right)

W=8+24W = 8 + 24

W=32 JW = 32 \mathrm{~J}

So the work done by the force during the displacement from x=0x = 0 to x=4 mx = 4 \mathrm{~m} is 32 Joules.

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