Answer:
Length of copper wire, l = 785 meters
Explanation:
Given that,
Resistance of the copper wire, R = 0.172 ohms
Area of cross section, 
Resistivity of copper, 
The resistance of a wire is given by :
l = 785 meters
So, the length of the copper wire is 785 meters. Hence, this is the required solution.
From
the problem statement, this is a conversion problem. We are asked to convert
from units of grams to units of kilograms. To do this, we need a
conversion factor which would relate the different units involved. We either
multiply or divide this certain value to the original measurement depending on
what is asked. From literature, we will find that 1000 grams is equal to 1 kilogram. We use this as follows:
<span> 1.440x10^6 g ( 1 kg / 1000 g ) = 1440 kg</span><span>
</span>
Answer:
Explanation:
Given
Weight of car 
mass of car 
velocity of car 
radius 
(a)Centripetal acceleration is given by
(b)Force that provide centripetal acceleration
(c)Friction force between car and tires is given by
where 
=coefficient of static friction
N=normal reaction
Centripetal force will balance the friction force
Energy is calculated as power*time, so give the wattage of 1200 W (equivalent to 1200 Joules/second) and time of 30 seconds, multiplying these gives 36000 J or 36 kJ of electrical energy.
If electrical charge or current is needed: Power = voltage * current, so given the power of 1200 watts and voltage of 120 V, current is 1200 W / 120 V = 10 Amperes. Charge is calculated by multiplying 10 A*30 s = 300 C.
