# A car is moving with a constant speed of $20 ms^{-1}$ against a resistive force of $100 \;N$. The power exerted by the car is

$(a)\;2\;KW \quad (b)\;5\;W \quad (c)\; 200 \;W \quad (d)\;1\;KW$

Power $P=F.v$
$\qquad\quad =100 \times 20$
$\qquad\quad=2 KW$
Hence a is the correct answer.

edited Feb 10, 2014 by meena.p