According to chapter 1 in the mixture of particles Article a mixture has to contain a serten size to mix with another particle so i would go with B size of the largest particle
Has mass and occupied space
Work = (500N)(15m)=7500J Power= (7500J)/(20s) =375 W
Hopefully this helps
We use the formula V=IR where I is current, v is voltage, and R is resistance. This is V=(3)(10) which is 30 Volts, answer choice (c)