<span>A lubricant such as oil, grease, graphite powder can reduce the friction between two surfaces. Or using metal balls to space them and reduce the contact surface area as used in ball bearings.</span>
For speed you can differentiate the equation, for acceleration you can again differentiate the equation .
at t=0 the particle is slowing down , when you get equation for velocity put t=0 then only -1 is left
A fixed volume is where either a solid or liquid has a volume that is constant under the same pressure and temperature. A gas cannot have a fixed volume because it changes by itself without any human interaction.
Best of Luck!
Answer:
A. it's the only answer that makes sense. if I'm wrong sorry
