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.
Answer (integer)
500
Solution
$\overrightarrow F = 20\widehat i + 10\widehat j$<br><br>$$\overrightarrow a = {{\overrightarrow F } \over m} = {{20\widehat i + 10\widehat j} \over 2} = 10\widehat i + 5\widehat j$$<br><br>$\therefore$ $$\overrightarrow s = {1 \over 2}\overrightarrow a {t^2} = {1 \over 2}\left( {10\widehat i + 5\widehat j} \right) \times {\left( {10} \right)^2}$$<br><br>$= 50\left( {10\widehat i + 5\widehat j} \right)m$<br><br>$\therefore$ Displacement along x-axis<br><br>= 50 $\times$ 10 = 500 m
About this question
Subject: Physics · Chapter: Laws of Motion · Topic: Newton's First Law
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