Question

Please solve question as soon as possible



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Answer 1

Answer:

the value of a is 5 joule is the answer

Answer 2

Answer:

Work done by the forces:

$\longrightarrow\rm W = \overrightarrow{F}. \overrightarrow{S}$

$\longrightarrow\rm 45 =(3\widehat{i} + 4 \widehat{j} - \alpha\widehat{k}) . (4\widehat{i} + 2\widehat{j} - \alpha\widehat{k})$

$\longrightarrow\rm 45 =12 + 8- \alpha^{2}$

$\longrightarrow\rm 45 + \alpha^{2} =12 + 8$

$\longrightarrow\rm 45 + \alpha^{2} =20$

$\longrightarrow\rm \alpha^{2} =20 - 45$

$\longrightarrow\rm \alpha^{2} =- 25$

$\longrightarrow\rm \alpha = \sqrt{ - 25}$

$\longrightarrow \underline{ \boxed{ \red{\bf \alpha = 5}}}$