Answer:
B) 2I
Explanation:
The equation that relates voltage, current and resistance is V=RI.
The equation for the resistance of a material in terms of its resistivity, length and cross-sectional area is 
In this case, the length is divided by 2 while keeping its resistivity (since it's the same material) and area, which means the resistance gets divided by 2. Then, looking at the equation I=V/R and keeping V constant, one deduces that since the resistance now is half than before then current now must be twice as before.
This is all intuitive in fact, cuting a homogeneous resistor in half and leaving the rest of the variables constant makes twice as easy for the electrons to cross the conductor, thus twice the current (one has to know that all the variables involved behave linearly, as the equations show).
Answer: 
Explanation:
The acceleration of the motorcycle is given by
where
v=24 m/s is the final velocity of the motorcycle
u=15 m/s is the initial velocity
t=3 s is the time taken
Substituting these numbers into the equation, we find
Answer:
The power of the corrective lenses is 3.162 D.
Explanation:
Given that,
Object distance = 70 cm
Image distance = 62 cm
Distance between eyes and glasses = 2.5 cm
Eyeglasses made of diverging corrective lenses can help her to see the apple clearly
So now ,
Object distance from glass =70-2.5 = 67.5 cm
Image distance from glass = 62-2.5 = 59.5 cm
We need to calculate the focal length
Using formula for focal length
We need to calculate the power of lens
Using formula of power
Negative sign shows the lens is diverging.
Hence, The power of the corrective lenses is 3.162 D.
Answer:
V = 4.63 m/s
V = 11.31 m/s
Explanation:
Given,
The distance traveled by the bus, towards north, d = 2.5 km
= 2500 m
The time taken by the trip is, t = 9 min
= 540 s
The velocity of the bus,
V = d / t
= 2500 / 540
= 4.63 m/s
At another point, the bus travels at a constant speed of v = 18 m/s
Therefore the velocity becomes
V = (4.63 + 18)/2
= 11.31 m/s
Hence, the velocity of the bus, V = 11.31 m/s
