The apple is lifted by 1.1 m
<u>Explanation</u>:
- Given that, mgh = 2 J and mass of apple = 180g
- Step 1: convert grams to kg as work is given in SI units.
180 g = 0.18 kg
- Step 2: substitute in the formula for work done.
0.18 * 10 * h = 2
- Step 3: calculate the value of h from this formula.
h = 2/1.8
h = 1.11 m
Answer:
the maximum intensity of an electromagnetic wave at the given frequency is 45 kW/m²
Explanation:
Given the data in the question;
To determine the maximum intensity of an electromagnetic wave, we use the formula;
=
ε₀cE
²
where ε₀ is permittivity of free space ( 8.85 × 10⁻¹² C²/N.m² )
c is the speed of light ( 3 × 10⁸ m/s )
E
is the maximum magnitude of the electric field
first we calculate the maximum magnitude of the electric field ( E
)
E
= 350/f kV/m
given that frequency of 60 Hz, we substitute
E
= 350/60 kV/m
E
= 5.83333 kV/m
E
= 5.83333 kV/m × (
)
E
= 5833.33 N/C
so we substitute all our values into the formula for intensity of an electromagnetic wave;
=
ε₀cE
²
=
× ( 8.85 × 10⁻¹² C²/N.m² ) × ( 3 × 10⁸ m/s ) × ( 5833.33 N/C )²
= 45 × 10³ W/m²
= 45 × 10³ W/m² × (
)
= 45 kW/m²
Therefore, the maximum intensity of an electromagnetic wave at the given frequency is 45 kW/m²
Heat flux (i) = k.a.temp variation/d
i = 250 J/s or 250w ; d = 2.1 x 10^-3m ; A = 1.9m^2 ; K (Body Fat) = 0.2W/m.Kelvin ; Temp. Var. (Delta T) = ?
-> 250 = 0.2 x 1.9 x deltaT/2.1 x 10^-3
-> 250 x 2.1 x 10^-3 = 0.38 x deltaT
-> 525 x 10^-3 = 38x10^-2 x deltaT
-> deltaT = 525 x 10^-3/ 38 x 10^-2
-> deltaT = 13.81 x 10^(-3 - (-2))
-> deltaT = 13.81 x 10^-1
-> deltaT = 1.381 K
Answer:
Coal and oil release sulfur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain. Fossil fuels release carbon dioxide when they burn, which adds to the greenhouse effect and increases global warming .
Explanation:
0.56 A is the current of the secondary coil.
transformer is the device that transfer electric energy from one AC circuit to another.
we know that ;
I ∝ 1/n;
where I IS CURRENT and n is NUMBER OF TURNS.
(I) secondary = X A
(n) secondary = 100
(I) primary = 0.04 A
(n) primary = 1400
USING THIS-----> I ∝ 1/n;
=>
0.04 A/X A =100/1400
=>X=0.56 A
as the current in the transformer is inversely proportional to the number of turns so 0.56 A is the current in the secondary coil.
learn more about transformers-
brainly.com/question/26991007
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