Which information is necessary to determine an object's speed?

1. distance and period of time.
2. distance and direction
3. period of time and direction
4. distance and change in position

1. distance and period of time.

Explanation:

The speed is calculated using the formula

"k" is the speed, "d" is the distance and "t" is the time.

You need distance and time to calculate the speed.

Speed is how fast an object is going. The direction is irrelevant to speed, not to be confused with velocity, which is speed in a given direction.

low freq = 100 mhz

low wavelength =101.7m

length = 3x10^8/freq

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .