Question

A $5.0\text{kg}$ block moves in a striaght line on a horizontal frictionless surface under the influence of a force that varies with position as shown in figure. How much work done by the force as the block moves from the origin to $x=8\text{m}$?

• A. $30\text{J}$
• B. $16\text{J}$
• C. $46\text{J}$
• D. $14\text{J}$

Answer 1

The correct option is D $14\text{J}$

Work done = area under graph=area of region $I$ + area of region $II$ + area of region $III$
$W=2\times 10+\frac{1}{2}\times 2\times 10-\frac{1}{2}\times 4\times 8W=20+10-16W=14\text{J}$