A. Using a combination lens made up of lenses, each of which has a different index of refraction. Is the correct answer.
Answer:
Explanation:
Capacitor of 0.75μF, charged to 70V and connect in series with 55Ω and 140 Ω to discharge.
Energy dissipates in 55Ω resistor is given by V²/R
Since the 55ohms and 140ohms l discharge the capacitor fully, the voltage will be zero volts and this voltage will be shared by the resistor in ratio.
So for 55ohms, using voltage divider rule
V=R1/(R1+R2) ×Vt
V=55/(55+140) ×70
V=19.74Volts is across the 55ohms resistor.
Then, energy loss will be
E=V²/R
E=19.74²/55
E=7.09J
7.09J of heat is dissipated by the 55ohms resistor
Answer:
3.0 x10^-3 J
Explanation:
The potential energy of a spring is given by PE = (0.5)k*x^2
Where
K: Spring Constant = 60 N/m
x: displacement of the spring from its equilibrium position = 1cm = 0.01m
Then PE = 0.5(60)(.01)^2 = 0.003J = 3.0 x10^-3 J
A-200 kg
I hope this helped xx
Answer: Current = 2 A
Explanation:
Given that an electrical power plant generates electricity with a
current I = 50 A
Potential difference V = 20 000 V
The resistance R will be achieved by Ohms law formula which state that
V = IR
But the power generated will be the product of potential difference and the current
Power P = IV
P = 50 × 20000
P = 1, 000000 W
When the transformer steps up the potential difference to 500 000 V before it is transmitted
Power is always constant.
Using the formula for power again with
V = 500000
1000000 = 500000× I
Make I the subject of formula
Current I = 1000000/500000
Current I = 2 A
