Name the element and explain why it is unusual:
a)A liquid metal
b)A non-metal that conducts electricity
Answer:
Refractive index = 1.15
Explanation:
As we know for constructive interference of reflected light the path difference of two reflected light rays must be integral multiple of the wavelength
so here we have
now here we know that
now we have
Answer:
v = 7.9 m/s
Explanation:
length of the vine (L) = 20 m
initial angle with the vertical = 45 degrees
final angle with the vertical = 30 degrees
acceleration due to gravity (g) = 9.8 m/s^{2}
speed (v) =?
to solve this problem we can apply the equation below:
loss in potential energy = gain in kinetic energy
m x g x h = 1/2 x m x
v =
before we can apply the above we need to get our height
height = initial vertical height - final vertical height
height = (L - L cosθ2) - (L - L cosθ1)
height = (20 - 20cos45) - (20 - 20cos30) = 3.2 m
v =
v = 7.9 m/s
Answer:
The length of the moment arm is 19 cm
Explanation:
Given;
The total length of the ruler, L = 40 cm
a mass is hung from its center mass, at 21 cm
a force, F is applied at 40 cm
The length of the moment arm is calculated as;
the center mass of the ruler is at 20 cm mark
0 21cm 40cm
--------------------------------------------------------------------
↓ r ↓
M F
Moment about F, = Fr
The length of the moment arm is = r
r = 40 cm - 21 cm
r = 19 cm
Therefore, the length of the moment arm is 19 cm
Answer:
Time period,
Explanation:
Given that,
The quartz crystal used in an electric watch vibrates with a frequency of 32,768 Hz, f = 32768 Hz
We need to find the period of the crystal's motion. The relationship between the frequency and the time period is given by :
T is the time period of the crystal's motion.
Time period is given by :
So, the time period of the crystal's motion is . Hence, this is the required solution.