Answer:
Explanation:
A )
speed of swimming in still water is given by the expression
distance / time
= 50 / 25
= 2 m /s
In lane 1 , 1.2 cm/s current is flowing in the direction that the swimmers are going so swimmers will cover distance at the rate of 2 + 1.2 = 3.2 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / 3.2 = 15.625 s
In lane 8 , 1.2 cm/s current is flowing against the direction that the swimmers are going so swimmers will cover distance at the rate of 2 - 1.2 = .8 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / .8 = 62.5 s
Answer: 0.86 × 10^14
Explanation:
Given the following :
Radius of proton = 1.2 × 10-15 m
Radius of hydrogen atom = 5.3 × 10-11 m
Density of proton could be calculated thus:
Mass of proton = 1.67 × 10^-27 kg
Using the formula :
(4/3) × pi × r^3
(4/3) × 3.142 × (1.2 × 10^-15)^3 = 7.24 × 10^-45
Density = mass / volume
Density = (1.67 × 10^-27) / ( 7.24 × 10^-45)
= 0.2306 × 10^18
Density of hydrogen atom:
Mass of hydrogen atom= 1.67 × 10^-27 kg
Using the formula :
(4/3) × pi × r^3
(4/3) × 3.142 × (5.3 × 10^-11)^3 = 6.24 × 10^-31
Density = mass / volume
Density = (1.67 × 10^-27) / ( 6.24 × 10^-31)
= 0.2676 × 10^4
Ratio is thus:
Density of proton / density of hydrogen atom
0.2306 × 10^18 / 0.2676 × 10^4 = 0.8617 × 10^14
Answer:
1353.38 Watt
Explanation:
T₁ = Initial temperature of the house = 35°C
T₂ = Final temperature of the house = 20°C
Δt = Time taken to cool the house = 38 min = 38×60 = 2280 s
m = mass of air in the house = 800 kg
Cv = Specific heat at constant volume = 0.72 kJ/kgK
Cp = Specific heat at constant pressure = 1.0 kJ/kgK
Heat removed
q = mCvΔT
⇒q = 800×720×(35-20)
⇒q = 8640000 J
Average rate of hear removal
∴ Power drawn by the air conditioner is 1353.38 Watt
V: velocity of wave
f: frequency
L: wavelenght
v = fL => L = v/f => L = (3x10^8)/(900x10^3) => L = 3.33 x 10^2m
