Answer:
4
Explanation:
We are given that
[tex]F_x=cx-3x^2[/tex]
K.E at x=0 m=20 J
K.E at x=3 m=11 J
We have to find the value of c.
By work energy theorem
Work done=Change in kinetic energy
W=[tex]\int_{0}^{3} Fdx=\int_{0}^{3}(cx-3x^2)dx[/tex]
[tex]W=[\frac{cx^2}{2}-x^3]^{3}_{0}[/tex]
[tex]W=\frac{9c}{2}-27[/tex]
[tex]\Delta K=11-20=-9 J[/tex]
[tex]-9=\frac{9c}{2}-27[/tex]
[tex]-9+27=\frac{9c}{2}[/tex]
[tex]18=\frac{9c}{2}[/tex]
[tex]c=\frac{2}{9}\times 18=4[/tex]
