Answer:
The speed of the wire is 5 m/s.
Explanation:
Given that,
Length = 20 cm
Magnetic field = 0.1 T
Current = 10 mA
Resistance 
We need to calculate the speed of the wire
Using formula of emf
Using formula of current
Put the value of 
into the formula of current
Hence, The speed of the wire is 5 m/s.
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:
39.240 W
Explanation:
Let's start by calculating the work done by the engine. We can assume that it is the same work done by the weight of the object to bring it from 40m to the surface: as much energy it takes to bring it up, the same ammount it takes to bring it down. Said work is 
At this point we can simply apply the definition of power, that is 
, to get the power of the engine is 
Because the box keeps going straight at the same speed, while the seat under it speeds up, slows down, or changes direction.
The cylinder has a volume of 37.46 cubic cm
