A car of mass m starts from rest and acquires a velocity along east v = vȋ (v>0) in two seconds. Assuming the car moves with uniform acceleration, the force exerted on the car is

(a) mv/2 eastward and is exerted by the car engine.

(b) mv/2  eastward and is due to the friction on the tyres exerted by the road.

(c) more than mv/2 eastward exerted due to the engine and overcomes the friction of the road.

(d) mv/2 exerted by the engine .

<p>This is a Multiple Choice Questions type Questions as classified in NCERT Exemplar</p><p><strong>Answer- b</strong></p><p><strong>Explanation</strong> – mass of car m =0</p><p>Initial velocity =0, </p><p>velocity at east direction = v? </p><p>Time =2s</p><p>So v=u+at, </p><p>v? =0+a (2)</p><p>so a =v/2? </p><p>F=ma = <span contenteditable="false"> <math> <mfrac> <mrow> <mrow> <mi>m</mi> <mi>v</mi> </mrow> </mrow> <mrow> <mrow> <mn>2</mn> </mrow> </mrow> </mfrac> <mi>? </mi> </math> </span>&nbsp;so force = mv/2 towards east.</p>

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