Answer:
3503.72 seconds
819.96 seconds
Explanation:
=Velocity of river = 0.566 m/s
=Velocity of student = 1.17 m/s
Distance to travel = 1.57 km = 1570 m
So,
Time = Distance / Speed

Time taken by the student to complete the trip is 3503.72 seconds
In still water

The difference in time between moving water and still water is 3503.72-2683.76 = 819.96 seconds
Answer:
Option B is the correct answer.
Explanation:
Thermal expansion

L = 1.2 meter
ΔT = 65 - 15 = 50°C
Thermal Expansion Coefficient for aluminum, α = 24 x 10⁻⁶/°C
We have change in length

New length = 1.2 + 1.44 x 10⁻³ = 1.2014 m
Option B is the correct answer.
Answer:
1.11
Explanation:
The index of the medium can be calculated using below formula
V= c/ n ............eqn(1)
Where V= velocity of the light is reduced to while traveling through the second medium= 2.7 x 10^8 m/s
n= index of the medium
c= speed of light= 3 x 10^8 m/s
Substitute for the values in eqn(1)
2.7 x 10^8 = (3 x 10^8 m/s)/ n
Making " n" subject of the formula, we have
n= (3 x 10^8 )/(2.7 x 10^8)
n= 1.11
Hence, the index of the medium is 1.11
Answer:
Lifetime = 4.928 x 10^-32 s
Explanation:
(1 / v2 – 1 / c2) x2 = T2
T2 = (1/ 297900000 – 1 / 90000000000000000) 0.0000013225
T2 = (3.357 x 10^-9 x 1.11 x 10^-17) 1.3225 x 10^-6
T2 = (3.726 x 10^-26) 1.3225 x 10^-6 = 4.928 x 10^-32 s