Answer:6g/cm³
Explanation:density=mass/volume
D=30/5
Density of marble=6g/cm³
Answer:
The resistance is .
Explanation:
Given that,
Power = 259 kV
Current = 429 A
Resistance
We need to calculate the current in each insulator
Using formula of current
Put the value into the formula
So all 95 insulators are in parallel
We need to calculate the resistance
Using formula of resistance
Put the value into the formula
Hence, The resistance is .
Answer:
Explanation:
The refractive index of the lens is
d = 1.570 dioptres
Therefore, her focal length is
f = 1 / d
f = 1 / 1.570
f = 0.6369 m
f = 63.69cm
The distance between the newspapers and her eyes is 42cm
Distance from her eye to the glasses is 2cm
We want to calculate her near point?
So, the distance between the newspaper and the glass
do = 42 - 2 = 40cm
The distance between the glass and the virtual image formed is given as
di = f•do / (do —f)
di = 63.69 × 40 / (40 — 63.69)
di = 2547.6cm / -23.69
di = —107.54cm
The relation use is obtain from the lens equation and the negative shows that virtual image formed.
The near point from her eye is
107.54 + 2 = 109.54cm
Answer:
4.988kW
Explanation:
According to the question, energy E extracted from the ocean breaker is directly proportional to the intensity I. It can be expressed mathematically as E ∝ I
E = kI where k is the constant of proportionality.
From the formula; k = E/I
This shows that increase in energy extracted will lead to increase in its intensity and vice versa.
If the device produces 10.0 kW of power on a day when the breakers are 1.20 m high
E = 10kW and I = 1.20m
k = 10/1.20
k = 8.33kW/m
To know how much energy E that will be produced when they are 0.600 m high, we will use the same formula
k = E/I where;
k = 8.33kW/m
I = 0.600m
E = kI
E = 8.33 × 0.6
E = 4.998kW
The device will produce energy of 4.998kW when they are 0.600m high.
This is because x is not an expanding part of the spring