How does a change in resistance affect the conductivity of a material?

a) the lower the resistance, the worse the conductivity

b) the lower the resistance, the better the conductivity

c) the higher the resistance, the better the conductivity

d) the change in resistance does not affect conductivity

ps. the answer is b) the lower the resistance, the better the conductivity

At time t=0, a particle is located at the point (3,6,9). it travels in a straight line to the point (5,2,7), has speed 8 at (3,6,9) and constant acceleration 2i−4j−2k. find an equation for the position vector of the particle.

Could someone . i have tried to solve myself but my calculation is off

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?