It's a measurement that's made up of two separate quantities ... its size AND its direction.
Some examples of vectors: force, displacement, velocity, acceleration. These things all have directions.
If one car is driving North at 30 mph and another car is driving West at 30 mph, then both cars have the same speed, but they have different velocities.
Velocity increases with speed
R = 0.407Ω.
The resistance R of a particular conductor is related to the resistivity ρ of the material by the equation R = ρL/A, where ρ is the material resistivity, L is the length of the material and A is the cross-sectional area of the material.
To calculate the resistance R of a wire made of a material with resistivity of 3.2x10⁻⁸Ω.m, the length of the wire is 2.5m and its diameter is 0.50mm.
We have to use the equation R = ρL/A but first we have to calculate the cross-sectional area of the wire which is a circle. So, the area of a circle is given by A = πr², with r = d/2. The cross-sectional area of the wire is A = πd²/4. Then:
R =[(3.2x10⁻⁸Ω.m)(2.5m)]/[π(0.5x10⁻³m)²/4]
R = 8x10⁻⁸Ω.m²/1.96x10⁻⁷m²
R = 0.407Ω
Answer: A
Explanation:
Proper Motion is the apparent angular motion of a star across the sky with respect to more distant stars. Typical proper motion is ~0.1 arcsec/year