Answer: 
Explanation:
Given
Cross-sectional area of wire 
Extension of wire 
Extension in a wire is given by
where, 
for same force, length and material
Divide (i) and (ii)
Before coming into conclusion first we have to understand both scalar and vector .
A scalar quantity is a physical quantity which has only magnitude for it's complete specification.
A vector quantity is that physical quantity which not only requires magnitude but also possesses direction for it's complete specification.
So the most important factor that differentiate vector from scalar is the direction.
As per the question the student is doing an experiment where he is recording the data obtained during the process.
In order to arrange them in data table, he should ask about the direction of the quantity under consideration.
Hence the correct option is the third option(C)i.e does the measurement include direction?
Answer:
v= 449.8 m/s
Explanation:
Given data
Frequency= 346Hz
Wave length= 1.4m
The expression below is used to find the speed
substitute
Hence the speed is v= 449.8 m/s
Answer:
Torque = R X F = R * F sin theta
-f * 2R will exert an equal opposite torque
-f * 2 = F sin theta
f = -F sin theta / 2
