Question

A 69 g particle is moving to the left at 25 m/s . How much net work must be done on the particle to cause it to move to the right at 31 m/s ? Express your answer to two significant figures and include the appropriate units.

Answer 1

Answer:11.59 J

Explanation:

Given

mass of Particle $m=69 gm$

Initially Particle moves towards left $v_1=25 m/s$

Final velocity of Particle is towards Right $v_2=31 m/s$

According to Work Energy theorem

Work done by all the Forces=change in Kinetic Energy

Work done by Force$=\frac{mv_2^2}{2}-\frac{mv_1^2}{2}$

$W=\frac{69\times 10^{-3}}{2}\left [ 31^-25^2\right ]$

$W=\frac{69\times 10^{-3}}{2}\left [ 961-625\right ]$

$W=11.59 J$