Answer:
Every option is correct except option C.
Option A is the most accurate statement of the law
Explanation:
C is incorrect because momentum of the SYSTEM is conserved and not necessarily that of the individual objects in the System.
For option B, momentum is a vector quantity but it does not describe the principal of conservation of momentum. Option D is also correct but does not state anything about the conservation of momentum.
Laws reflect scientific knowledge that experiments have repeatedly verified (and never falsified). Their accuracy does not change when new theories are worked out, but rather the scope of application, since the equation (if any) representing the law does not change.
Answer:
Length L=0.0125 m
Explanation:
Given data
Resistance R=0.11Ω
Temperature T=20°C
Resistivity of tungsten at 20°C p=5.6×10⁻⁸Ω.m²
Radius of filament r=0.09/2 =0.045 mm =0.045×10⁻³m
To find
Length of filament L
Solution
The Cross section of area of filament is given as:
The Resistance of a material is given as:
We can see it as two movements: one on the north-south axis and one on the west-east axis.
On the north-south Axis, the hiker went 8 km north and 4 km south, so in total the hiker went 4 km north (we can subtract one for the other and the direction remains that which was bigger)
On the west-easth Axis, the hiker went 6 km east and 6 km west, so in total the hiker didn't move on this axis! or, he/she moved but then "came back"
So in total, the hiker only moved4 km north - answer B.
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