A particle has an initial velocity $3 \hat{i}+4 \hat{j}$ and an acceleration of $0.4 \hat{i}+0.3 \hat{j}$. Its speed after 10 s is

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Aicharya · Accepted Answer

$ \begin{aligned} \overrightarrow{\mathrm{u}} & =3 \hat{\mathrm{i}}+4 \hat{\mathrm{j}} ; \overrightarrow{\mathrm{a}}=0.4 \hat{\mathrm{i}}+0.3 \hat{\mathrm{j}} \ \overrightarrow{\mathrm{u}} & =\overrightarrow{\mathrm{u}}+\overrightarrow{\mathrm{a}} \mathrm{t} \ & =3 \hat{\mathrm{i}}+4 \hat{\mathrm{j}}+(0.4 \hat{\mathrm{i}}+0.3 \hat{\mathrm{j}}) 10=3 \hat{i}+\hat{\mathrm{j}}+4 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}=7 \hat{\mathrm{i}}+7 \hat{\mathrm{j}} \end{aligned} $ Speed is $\sqrt{7^2+7^2}=7 \sqrt{2}$ units

A particle has an initial velocity $3 \hat{i}+4 \hat{j}$ and an acceleration of $0.4 \hat{i}+0.3 \hat{j}$.…

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