The Position of A $3.2 - \mathrm { kg }$ Particle Is Given By

Multiple Choice

The position of a $3.2 - \mathrm { kg }$ particle is given by $x ( t ) = b t ^ { 3 }$ , where $b = 6.5 \mathrm {~m} / \mathrm { s } ^ { 3 }$ . What is the force acting on the particle at time $t = 8$ seconds?

A) 1000 N
B) 670 N
C) 520 N
D) 800 N