Question 182: Laws of Motion

Question

A boy pushes a box of mass 2 kg with a force $$\overrightarrow F  = \left( {20\widehat i + 10\widehat j} \right)N$$ on a frictionless surface. If the box was initially at rest, then ___________ m is displacement along the x-axis after 10s.

Accepted Answer

$$\overrightarrow F  = 20\widehat i + 10\widehat j$$
$$\overrightarrow a  = {{\overrightarrow F } \over m} = {{20\widehat i + 10\widehat j} \over 2} = 10\widehat i + 5\widehat j$$
$$ 	herefore $$ $$\overrightarrow s  = {1 \over 2}\overrightarrow a {t^2} = {1 \over 2}\left( {10\widehat i + 5\widehat j} ight) 	imes {\left( {10} ight)^2}$$
$$ = 50\left( {10\widehat i + 5\widehat j} ight)m$$
$$ 	herefore $$ Displacement along x-axis
= 50 $$	imes$$ 10 = 500 m

Laws of Motion

A boy pushes a box of mass 2 kg with a force $\overrightarrow F = \left( {20\widehat i + 10\widehat j} \right)N$ on a frictionless surface. If the box was initially at rest, then ___________ m is displacement along the x-axis after 10s.

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