Answer: B
Explanation:
Limiting the maximum current through the bulb. This will help in preserving or improving the bulb's lifetime and also this won't have an effect on the brightness of the bulb as brightness is affected by the average value. Although brightness is a factor of current, reducing the maximum current won't have any bearing on the average current the bulb is getting.
NOTE: The given question is incomplete.
<u>The complete question is given below.</u>
The human eye contains a molecule called 11-cis-retinal that changes conformation when struck with light of sufficient energy. The change in conformation triggers a series of events that results in an electrical signal being sent to the brain. The minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kJ/mole. Calculate the longest wavelength visible to the human eye.
Solution:
Energy (E) = 164 kJ/mole
E = 164 kJ/mole = 164 kJ /6.023 x 10²³
= 2.72 x 10⁻²² kJ = 2.72 x 10⁻¹⁹J
Planck's constant = 6.6 x 10⁻³⁴ J s,
Speed of light = 3.00 x 10⁸ m/s
Let the required wavelength be λ.
Formula Used: E = hc / λ
or, λ = hc / E
or, λ = (6.6 x 10⁻³⁴ J s)× (3.00 x 10⁸ m/s) / (2.72 x 10⁻¹⁹J)
or, λ = 7.28 x 10⁻⁷ m
or, λ = (7.28 x 10⁻⁷ m) ×( 1.0 x 10⁹ nm / 1.0 m)
or, λ = (7.28 x 10² nm)
or, λ = 728 nm
Hence, the required wavelength will be 728 nm.
Answer:
(A) Q = 2.26×10⁶J
(B) ΔT = 9°C
(C)
Explanation:
We have been given the mass of the hiker, the volume of water from which we can calculate the mass knowing that the density if water is 1000kg/m³.
Evaporation is a phase change and occurs at a constant temperature. We would use the latent heat of vaporization to calculate the amount of heat evaporated.
We would then equate this to the heat change it brings about in the hiker's body and then calculate the temperature drop.
See the attachment below for full solution.
Answer:
f_D = =3.24 N/m
Explanation:
data given
properties of air
k = 0.0288 W/m.K
WE KNOW THAT
Reynold's number is given as
= 1.941 *10^4
drag coffecient is given as
solving for f_D
Drag coffecient for smooth circular cylinder is 1.1
therefore Drag force is
f_D = =3.24 N/m
Answer: 51841.5 Watts
Explanation: Using the kinematic equation for the final velocity for a constant acceleration we have:
Vf=Vi+a*t
replacing the values the results is
a=(Vf-Vi)/t= (30.55 m/s-19.44 m/s)/5s= 2.22 m/s^2
Remenber that to convert the speed in Km/h to m/s we have to multiplier by the factor 0.277.
Finally to calculate the increment of power get the final velocity we have to use Neton second law to determine the Force applied to the car.
F=m* a=2100 Kg* 2.22 m/s^2= 4666.2 N
Then increment power to accelerate is given by:
ΔPower= Force* Δ velocity= 4666.2 N* 11,11 m/s= 51841.5 Watts
