Question 102: Work, Energy and Power & Circular Motion

Question

A particle experiences a variable force $$\overrightarrow F  = \left( {4x\widehat i + 3{y^2}\widehat j} \right)$$ in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane, then Kinetic Energy changes by :

Accepted Answer

$$W = \int {\overrightarrow F \,.\,d\overrightarrow r } $$
$$ = \int\limits_1^2 {4xdx + \int\limits_2^3 {3{y^2}dy} } $$
$$ = [2{x^2}]_1^2 + [{y^3}]_2^3$$
$$ = 2 	imes 3 + (27 - 8)$$
$$ = 25$$ J

Answer

50.0 J

Answer

12.5 J

Answer

25.0 J

Answer

0 J

Work, Energy and Power & Circular Motion

A particle experiences a variable force $\overrightarrow F = \left( {4x\widehat i + 3{y^2}\widehat j} \right)$ in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane, then Kinetic Energy changes by :

Choose the correct answer: