Question

The potential energy of a conservative system is given by $U=a{y}^2-by$, where $y$ represents the position of the particle, both $a$ and $b$ are constants. What is the force acting on the system?

• A. $-ay$
• B. $-by$
• C. $2ay-b$
• D. $b-2ay$

Answer 1

The correct option is D $b-2ay$

$F=-\frac{dU}{dy}$
$F=-\frac{d(a{y}^2-by)}{dy}$

$F=b-2ay$