Vector quantities have both magnitude and direction. Distance is a scalar quantity. It refers only to how far an object has traveled. For example, 4 feet is a distance; it gives no information about direction.
The resistance of a given conductor depends on its electrical resistivity (
), its length(L) and its cross-sectional area (A), as follows:
In this case, we have 
, 
and 
. So, the total resistance of the wire with length of 138m is:
Given data
Power (P) = 50 hp,
= 50 × 746, we know that 1 hp = 746 W.
= 37300 Watts (Watt = J/s)
Work = 6.40 ×10⁴ J
Power is defined as rate of doing work and the unit of power is<em> Watt.</em>
Mathematically,
Power = (Work / time) Watts
= 6.40 ×10⁴ / time
37300 W = 6.40 ×10⁴ J /time (Where time in seconds)
=> time = Work/Power
= 6.40 ×10⁴/37300
= <em>1.74 seconds </em>
<em> </em><em>Therefore , the engine need 1.74 seconds to do 6.40 6.40 ×10⁴ J of work </em>
<em> </em>
<span>The blades should turn in two directions.</span>
From the given problem, a limit on the depression of a building is placed at 20 centimeters. To solve how many floors can be safely added, a quantity of how many cm will a building sink for each floor that is added is needed. Unfortunately, it is not found anywhere in the problem. However, we can provide a formula to solve for the depression. This is as follows:
Building depression < 20 cm
Building depression = (cm depression per floor) * (no. of floors)
