Answer:
Diameter will be 351.42 mm
Explanation:
We have given current flowing in the copper wire i = 310 A
Voltage drop across the wire V = 0.55 volt
We know that resistance is given by 
Length of the copper wire l = 1 m
Resisitivity of the copper wire 
We know that resistance 


As area 


So diameter
= 351.42 mm
Answer: 
Explanation:
Given
Wavelength of light 
Screen is
away
Distance between two adjacent bright fringe is 
When same experiment done in water, wavelength reduce to 
So, the distance between the two adjacent bright fringe is 
Keeping other factor same, distance becomes

Answer:
13.5 m
Explanation:
M = Mass of cart = 500 kg
m = Ann's mass = 50 kg
= Velocity of Ann relative to cart = 5 m/s
= Velocity of Cart relative to Ann
As the linear momentum of the system is conserved

Time taken to reach the right end by Ann

Distance the cart will move in the 3 seconds

The negative sign indicates opposite direction
Movement of Ann will be the sum of the distances

The net movement of Ann is 13.5 m
I got inner ear for my answer if wrong sorry
1.53 m/s toward the beach
Explanation:
The magnitude of the velocity of the runner is given by:

where
d is the displacement of the runner
t is the time taken
In this case, d=110 m and t=72 s, so the velocity of the runner is

Velocity is a vector, so it consists of both magnitude and direction: we already calculate the magnitude, while the direction is given by the problem, toward the beach.