Answer:
The cost of using the hair dryer for 15 minutes is 
Explanation:
The parameters given in the question are;
The electric current drawn by the the air dryer, I = 11 A
The voltage to which the hair dryer is connected, V = 120 V
The duration of usage of the hair dryer = 15 minutes = 60 minutes /4 = 1 hour/4 = 0.25 hour
The electrical energy costs $0.09/kW·h
The power consumed by the hair dryer = I × V = 11 × 120 = 1320 Watts = 1.32 kW
The energy used by the hair dryer in 15 minutes (0.25 hour) = 1.32 × 0.25 0.33 kW·h
The energy used by the hair dryer in 15 minutes (0.25 hour) = 0.33 kW·h
The energy cost = $0.09/(kW·h)
Therefore;
The cost of using the hair dryer for 15 minutes (0.25 hour) = 0.33 kW·h/($0.09/(kW·h)) = $33/9 = $3 2/3 = $3.6
.
Answer:
r= 3.2 cm
Explanation:
Given that
I= 8.7 A
B= 5.4 x 10⁻⁵ T
μo=1.25664 x 10⁻⁶
We know that magnetic filed in wire at a distance r given as
By putting the values
r=0.032 m
r= 3.2 cm
Kilogram(kg)
It's not the SI unit of mass in the metric system however.
Answer:
Explanation:
thickness of oil t = 200 nm
index of refraction μ = 1.5
For transmitted light :---
path difference = 2μ t
For constructive interference
path difference = n λ , λ is wavelength of light
2μ t = n λ
λ = 2μ t / n
For longest λ , n = 1
λ = 2μ t
= 2 x 1.5 x 200 nm
= 600 nm
Wavelength in water
= 600 / refractive index of water
= 600 / 1.33
= 451.1 nm Ans
Answer:
1400 N
Explanation:
Change in momentum equals impulse which is a product of force and time
Change in momentum is given by m(v-u)
Equating this to impulse formula then
m(v-u)=Ft
Making F the subject of the formula then
Take upward direction as positive then downwards is negative
Substituting m with 0.3 kg, v with 2 m/s, and u with -5 m/s and t with 0.0015 s then
