Answer:51.44 units
Explanation:
Given
x component of vector is 
y component of vector is 
so position vector is

Magnitude of vector is


|r|=51.44 units
Direction

vector is in 2nd quadrant thus


Answer:
32cm³
Explanation:
Given parameters:
Density of substance = 2.7g/cm³
Mass of substance = 86.4g
Unknown:
Volume of substance = ?
Solution:
Density is the mass per unit volume of a substance.
Density = 
Since the unknown is volume we solve for it;
mass = density x volume
86.4 = 2.7 x volume
volume =
= 32cm³
Answer:
A. Their same forces repel each other, and their opposite forces attract each other.
Explanation:
As we know by the property of electric charge that similar charges repel each other and opposite charges attracts each other
So here we have similar situation in magnets also
Two similar poles or like poles of magnet i.e. North - North poles or South - South poles always repel each other
And also we can see that opposite poles of magnet each other i.e. North pole and south pole always attract each other.
SO here correct answer is
A. Their same forces repel each other, and their opposite forces attract each other.
72 m/s
Explanation:
Given,
Frequency ( f ) = 6 Hz
Wavelength ( λ ) = 12 m
To find : -
Speed ( v ) = ?
Formula : -
v = f x λ
v
= 6 x 12
= 72 m/s
Therefore,
the speed of a wave with a frequency of 6 Hz and a wavelength of 12 m is 72 m/s.
Explanation:
Young' modulus is the ratio of normal stress to the longitudinal strain. Mathematically, it is given by :
Normal stress is given by force per unit area. Longitudinal strain is the change in length per unit original length.
The mathematical definition of Young's modulus is given by :
..........(1)
Where
is the change in length
F is the force
A is the area of cross section
So, the Young's modulus refers to the change in length of the object. Hence, the correct option is (b) "length".